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Plates moving due to convection in mantle | Cosmology & Astronomy | Khan Academy

Video vocabulary

definitive

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US / dɪˈfɪnətɪv /

UK / dɪˈfɪnɪtɪv /

B2
  • adjecitve
  • Clear and leaving no further question

already

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US / ɔ:lˈredi /

UK / ɔlˈrɛdi /

A1
  • adverb
  • Having happened or been done before this time

imagine

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US / ɪ'mædʒɪn /

UK / ɪˈmædʒɪn /

A1
  • verb
  • To think creatively about; form mental picture of

fluid

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US / 'flu:ɪd /

UK / ˈfluɪd /

B2
  • adjecitve
  • A material that can easily flow, e.g. water
  • Able to move smoothly or gracefully
  • Changing often and without warning
  • noun
  • Liquid that flows smoothly, such as water

thick

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US / θɪk /

UK / θɪk /

A2
  • adjecitve
  • Difficult to see through, as fog
  • Full of (people, etc.)
  • (Of a liquid) that moves or pours slowly
  • Stupid; not smart
  • (Of person's accent) hard to understand
  • Having a large distance between two surfaces

flow

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US / fləʊ /

UK / flo /

A2
  • noun
  • Amount of something that moves through an area
  • verb
  • To move steadily and easily in a certain direction

area

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US / 'eərɪə /

UK / ˈɛriə /

A1
  • noun
  • Amount of measured space
  • A specific section or space; part of a region
  • A subject or field of study

vibrate

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US / vaɪˈbreɪt /

UK / ˈvaɪˌbret /

B2
  • verb
  • To shake side to side quickly in small movements

always

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US / 'ɔ:lweɪz /

UK / ˈɔlwez,-wɪz,-wiz /

A1
  • adverb
  • For a very long time
  • At all times; in every situation
  • For ever

point

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US / pɔɪnt /

UK / pɔɪnt /

A1
  • noun
  • An item to be discussed
  • Small spot or dot
  • Fact or detail
  • Feature of something
  • The size of the text on a page or screen
  • A certain time or stage in a process
  • Certain position in time or space
  • Idea or fact you try to convince people about
  • Measurement of scores in a game, sport
  • Sharp end of something, e.g. a pen or pin
  • verb
  • To face a certain direction, e.g. north
  • To indicate something with your finger to others

should

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US / ʃʊd /

UK / ʃʊd /

A1
  • other
  • Used to indicate what is proper or reasonable

actually

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US / ˈæktʃuəli /

UK / ˈæktʃuəli /

A1
  • adverb
  • Used to add new (often different) information

liquid

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US / ˈlɪkwɪd /

UK / ˈlɪkwɪd /

A2
  • adjecitve
  • (Of wealth) being able to be spent as cash
  • In a state of being uncertain
  • Moving in a flowing manner, like water or oil
  • noun
  • Something that is similar to the state of water

contain

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US / kənˈteɪn /

UK / kənˈten /

A2
  • verb
  • To keep something from spreading
  • To hold something inside something else

reason

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US / 'ri:zn /

UK / ˈrizən /

A1
  • noun
  • Ability to think about facts and form a judgment
  • Explanation for why something occurred or was done
  • verb
  • To think and make conclusions in a logical manner

here

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US / hɪə(r) /

UK / hɪr /

A1
  • adverb
  • In this place; at this location, position or time

surround

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US / səˈraʊnd /

UK / səˈraʊnd /

A2
  • other
  • To be closely connected to and have an effect on
  • verb
  • To be all the way around something
  • To be closely connected to and have an effect on
  • To move closer on all sides of something

once

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US / wʌns /

UK / wʌns /

A1
  • adverb
  • One time; one instance
  • At a time in the past
  • conjunction
  • When; as soon as

certain

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US / ˈsə:tn /

UK / ˈsɚtn /

A1
  • adjecitve
  • Definite, fixed
  • Referring to an unspecified amount or quantity
  • Being sure about something; without doubt

pot

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US / pɒt /

UK / pɑt /

A2
  • noun
  • Container designed to hold or store something
  • Deep, round container that is used for cooking
  • Large, significant quantity of something
  • Slang name for marijuana
  • Net pocket at the corners, etc. of a snooker table
  • Money that can be won in a card game or a bet
  • verb
  • To plant something in a container filled with soil
  • To hit a ball into a table pocket in snooker

boiling

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US / ˈbɔɪlɪŋ /

UK / ˈbɔɪlɪŋ /

A2
  • adjecitve
  • Being boiled in water
  • verb
  • To become extremely angry or excited
  • To cook in very hot water
  • To make liquids hot so they turn to gas

heat

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US / hi:t /

UK / hit /

A2
  • noun
  • State of anger, excitement, or arguing
  • Particular temperature at which to cook something
  • High temperature
  • One of series of races to find the finalists
  • Hot temperature, conditions, or weather
  • verb
  • To make hot or hotter

past

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US / pɑ:st /

UK / pæst /

A2
  • adjecitve
  • No longer current or new
  • adverb
  • So as to go beyond, or further than something
  • noun
  • Time that existed before now, e.g. long ago
  • preposition
  • After a particular time
  • At a later point in distance; beyond

gravitational

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US / ˌgrævɪˈteɪʃənl /

UK / ˌɡrævɪˈteɪʃənl /

C1
  • adjecitve
  • Concerning the force of gravity

container

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US / kənˈteɪnə(r) /

UK / kənˈtenɚ /

A2
  • noun
  • An object that can be used to hold things

probably

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US / ˈprɒbəbli /

UK / ˈprɑbəbli /

A1
  • adverb
  • That is likely to happen or be true

will

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US / wɪl /

UK / wɪl /

A1
  • noun
  • Desire or choice of someone
  • Document saying who gets your money when you die
  • Strong desire to do something; determination
  • Desire to do something; strong wish to do
  • other
  • Used with verbs to express the future
  • verb
  • To leave property to someone after your death
  • To use mental effort to make something happen
  • Am (is, are) likely to do
  • To influence someone to do something
  • To make something happen by strongly wanting it

side

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US / saɪd /

UK / saɪd /

A1
  • adjecitve
  • In addition to the central or most important thing
  • Next to, or very close to, the right or left of
  • noun
  • Position or opinion that is opposite to another
  • Right or left part of a person's body
  • Feature of someone's personality
  • Straight edge of an object
  • One of two or more groups fighting each other
  • verb
  • To decide to agree with one point, not the other

similar

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US / ˈsɪmələ(r) /

UK / ˈsɪməlɚ /

A1
  • adjecitve
  • Nearly the same; alike

energy

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US / 'enədʒɪ /

UK / ˈɛnədʒi /

A2
  • noun
  • Physical or mental strength

again

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US / ə'ɡen /

UK / əˈɡɛn /

A1
  • adverb
  • One more time, once more

that

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US / ðæt /

UK / ðæt, ðət /

A1
  • adjecitve
  • The person or thing being talked about
  • Used to identify something both the speakers know
  • adverb
  • Used to reinforce adjectives and adverbs
  • To such a degree
  • conjunction
  • Used to connect a noun clause
  • Used to introduce an adverbial clause
  • Used to introduce a noun clause
  • determiner
  • Used as a noun to refer to something
  • pronoun
  • Referring an object far away
  • Used to refer to the relative pronoun ‘which’

like

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US / laɪk /

UK / laɪk /

A1
  • adjecitve
  • Being equal in status or kind to something else
  • Similar; the same
  • adverb
  • For example
  • preposition
  • Used as a filler; used to ad emphasis
  • In a way similar to the way something is done
  • Such as; for example
  • verb
  • To want to
  • To find something pleasing; to prefer something

about

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US / ə'baʊt /

UK / əˈbaʊt /

A1
  • adverb
  • To be ready to; going to
  • Nearly; approximately; roughly
  • Near; next to; close to
  • In every direction; in the area of
  • preposition
  • Concerning or of (a topic)

drag

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US / dræɡ /

UK / dræɡ /

A2
  • noun
  • Force of air pushing back against a plane car etc.
  • Boring or annoying thing/activity
  • verb
  • To reluctantly move or go somewhere
  • To feel that progress or time is moving slowly
  • To pull something heavy or difficult along the ground

first

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US / fɜ:st /

UK / fɚst /

A1
  • adjecitve
  • 1st; Coming before all others in time or place
  • noun
  • Something that has not happened before
  • Position of the winner of a competition

place

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US / pleɪs /

UK / ples /

A1
  • noun
  • Particular location, area or region
  • verb
  • To put someone in a particular type of situation
  • To put something in a certain location or position

even

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US / 'i:vn /

UK / ˈivən /

A1
  • adjecitve
  • Being equal in influence, power, possibility etc.
  • Being divided equally or fairly
  • (Of teams/contest) with similar chances of success
  • Smooth, level, or regular
  • Can be divided by 2; ending in 2, 4, 6, 8, or 0
  • At a regular, equally steady manner
  • Remaining steady and unchanging
  • adverb
  • (When this is surprising) as well; too
  • (Used to compare two things/stress the difference)
  • verb
  • To make something level; to flatten
  • To make something equal

sink

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US / sɪŋk /

UK / sɪŋk /

A2
  • noun
  • Large bowl in a kitchen or washroom for washing
  • verb
  • To push something down into the ground
  • To dig (a well)
  • To move down toward a lower point
  • To decrease in value or amount

bunch

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US / bʌntʃ /

UK / bʌntʃ /

B1
  • noun
  • A group of things of the same kind
  • verb
  • To group people or things closely together
  • (Cloth) to gather/be gathered together in folds

thicken

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US / ˈθɪkən /

UK / ˈθɪkən /

B1
  • verb
  • To make something more dense or concentrated
  • To become more complex or difficult to understand
  • To make thicker

right

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US / raɪt /

UK / raɪt /

A1
  • adjecitve
  • Correct or true
  • The south side of you looking at the rising sun
  • adverb
  • Exactly in a place or time
  • Being appropriate for a particular event
  • In a straight or direct manner
  • noun
  • Something you are legally or morally allowed to do
  • Ideal of what is just and good
  • Political view based on conservatism
  • verb
  • To fix something previously wrong or unjust
  • To make upright, as a boat that has turned over

essentially

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US / ɪˈsenʃəli /

UK / ɪˈsenʃəli /

A2
  • adverb
  • Basically; (said when stating the basic facts)

happen

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US / 'hæpən /

UK / ˈhæpən /

A1
  • verb
  • To take place or occur

cause

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US / kɔ:z /

UK / kɔz /

A2
  • noun
  • Belief, goal or organization that people support
  • Reason for
  • verb
  • To make something happen; create effect or result

then

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US / ðen /

UK / ðɛn /

A1
  • adverb
  • A time that is not now
  • Following another thing in time or arrangement
  • Following on reasonably from what was just stated
  • At that time, not now

case

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US / keɪs /

UK / kes /

A1
  • noun
  • Container used to carry things, e.g. clothes
  • Set of facts about a crime
  • Set of facts about an event
  • Example or instance of something
  • verb
  • To find out about a place, as in planning to steal

current

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US / 'kʌrənt /

UK / ˈkɚrənt, ˈkʌr- /

A2
  • adjecitve
  • Happening or being in the present time
  • noun
  • Electricity flowing through wires
  • Movement of water in a river, or air in the sky

nothing

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US / 'nʌθɪŋ /

UK / ˈnʌθɪŋ /

A1
  • noun
  • Item of little or no value, importance, interest
  • Number or value of zero
  • pronoun
  • Not anything, not a single thing

enough

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US / ɪˈnʌf /

UK / ɪˈnʌf /

A1
  • adjecitve
  • Sufficient to answer the need
  • adverb
  • To a satisfactory degree
  • pronoun
  • Equal to what is needed; as much as required
  • Adequate number or amount

down

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US / daʊn /

UK / daʊn /

A1
  • adjecitve
  • Being sad, sick, or unhappy
  • Not operating, working, or functioning as expected
  • adverb
  • In a sitting or lying position
  • Towards or on the ground, floor, or bottom
  • Written or copied onto a piece of paper or book
  • noun
  • A period of play in American Football
  • The soft, smooth hairs that cover a bird's body
  • preposition
  • Along something's path, course, or direction
  • Going from a higher position to a lower position
  • verb
  • To eat or drink very quickly and without stopping

mix

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US / mɪks /

UK / mɪks /

A2
  • noun
  • A combination of more than two things
  • verb
  • To combine two or more things to make one
  • To meet and get along with others, e.g. at a party

each

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US / i:tʃ /

UK / itʃ /

A1
  • determiner
  • Every one of two or more things
  • pronoun
  • Per one person or thing

type

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US / taɪp /

UK / taɪp /

A1
  • noun
  • Printed letters or blocks used for printing them
  • Group of things or people sharing common features
  • verb
  • To identify something belonging to a group
  • To write by touching keys on a keyboard

eventually

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US / ɪˈventʃuəli /

UK / ɪˈvɛntʃuəli /

A2
  • adverb
  • After a long time; after many attempts; in the end

get

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US / ɡet /

UK / ɡɛt /

A1
  • verb
  • To become affected by illness or disease
  • To begin to feel or understand an emotion or idea
  • To send or bring someone or something home, etc.
  • To go somewhere to obtain something
  • To (cause to) do a particular thing
  • To obtain, receive or be given something
  • To currently have
  • To prepare for use
  • To understand something being said or read

what

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US / wɒt /

UK / hwɑt, hwʌt, wɔt, wʌt,hwət, wət /

A1
  • pronoun
  • Thing or things that; the same kind as
  • Used to emphasize something you are about to say
  • adjecitve
  • Used to refer to a particular amount, or number
  • Used to place emphasis on a particular quality
  • adverb
  • To a certain degree
  • determiner
  • Question words used for asking for information
  • exclamation
  • Used to express excitement, shock, or surprise
  • Used to ask people to repeat something they said

this

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US / ðɪs /

UK / ðɪs /

A1
  • adjecitve
  • Used to indicate something already been discussed
  • Used to indicate something happening around now
  • adverb
  • An indication by a physical motion or gesture
  • A specific amount of
  • determiner
  • Person, thing, or idea near you
  • pronoun
  • Person, thing that has already been discussed

although

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US / ɔ:lˈðəu /

UK / ɔlˈðo /

A1
  • conjunction
  • Despite the fact that; however

able

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US / 'eɪbl /

UK / ˈebəl /

A2
  • adjecitve
  • Skilled; good at something
  • Having the ability to do something

might

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US / maɪt /

UK / maɪt /

A1
  • other
  • Used to politely request an action
  • Used to express that something could happen
  • Power, strength, force or influence

than

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US / ðən /

UK / ðən /

A1
  • conjunction
  • Used to compare two things that are not equal

rock

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US / rɒk /

UK / rɑk /

A1
  • noun
  • Type of popular music with a strong, loud beat
  • Strong, tough person who can be relied upon
  • Big stone; hard, solid substance forming mountains
  • verb
  • To be greatly upset by something, e.g. a death
  • To be extremely effective or pleasing
  • To play, sing along with, or dance to heavy music
  • To move back and forth or from side to side

pull

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US / pʊl /

UK / pʊl /

A1
  • noun
  • Act of breathing in smoke, as from a pipe
  • Force something has that draws other things to it
  • Using your hands to move something to you
  • verb
  • To breathe in smoke, as from a pipe
  • To hold something and move it toward you
  • To remove something by force

rigid

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US / ˈrɪdʒɪd /

UK / ˈrɪdʒɪd /

B1
  • adjecitve
  • Stiff rather than flexible
  • Very fixed in your opinion or habits

also

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US / 'ɔ:lsəʊ /

UK / ˈɔlso /

A1
  • adverb
  • In addition; too; in a similar way

term

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US / tɜ:m /

UK / tɚm /

A1
  • noun
  • Conditions applying to an agreement, contract
  • Length of time something is expected to happen
  • Fixed period of weeks for learning at school
  • The (precise) name given to something
  • verb
  • To call; give a name to

less

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US / les /

UK / lɛs /

A1
  • adjecitve
  • Smaller in amount or degree
  • adverb
  • To a smaller degree
  • noun
  • A smaller amount
  • preposition
  • With the subtraction of

let

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US / let /

UK / lɛt /

A1
  • verb
  • To allow someone to do something
  • Introducing a suggestion to do something together
  • To rent a house, etc. to others

level

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US / 'levl /

UK / ˈlɛvəl /

A2
  • adjecitve
  • (Sports) equal to another
  • Being steady and determined (e.g. a voice)
  • noun
  • Specific height of something
  • Amount of ability you have compared to others
  • Floor or deck within a building
  • Tool used to determine if something is lying flat
  • verb
  • To aim a gun at someone
  • To destroy a building; flatten an area completely
  • To make things flat or even
  • To make a score equal to another, in sports

ones

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US / wʌnz /

UK / wʌnz /

A1
  • number
  • Number 1, a single person or thing

other

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US / 'ʌðə(r) /

UK / ˈʌðər /

A1
  • adjecitve
  • A thing different from that mentioned
  • determiner
  • (Something) else; not the first (one)
  • pronoun
  • Being the one and only thing of that category

kind

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US / kaɪnd /

UK / kaɪnd /

A1
  • adjecitve
  • In a caring and helpful manner
  • friendly and considerate
  • noun
  • One type of thing

circular

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US / ˈsɜ:kjələ(r) /

UK / ˈsɜ:rkjələ(r) /

B2
  • adjecitve
  • Shaped like a circle or part of a circle
  • noun
  • Paper with news, ads, etc. sent round to people

the

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US / ðə /

UK / ðə /

A1
  • article
  • Used to refer to something already mentioned
  • Used to show there is only one of something
  • determiner
  • Used to describe all of a family

lead

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US / li:d /

UK / lid /

A1
  • adjecitve
  • Being the main part in movies or plays
  • noun
  • Wire for electricity, computer, etc.; cable
  • Information that could help to solve a crime
  • Main part in a play or movie
  • Heavy, gray metal element
  • Rope used to tie something to stop it escaping
  • Act of being at the front in a race or game
  • verb
  • To show the way or guide others
  • To be at the front of a race or game
  • To travel in front of; go in advance of others

one

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US / wʌn /

UK / wʌn /

A1
  • pronoun
  • You; we; people in general; someone
  • The thing or person previously referred to
  • adjecitve
  • Used to refer to people generally
  • Being a strong example of (something mentioned)
  • number
  • Number 1

material

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US / məˈtɪəriəl /

UK / məˈtɪriəl /

A2
  • adjecitve
  • Relevant; (of evidence) important or significant
  • Belonging to the world of physical things
  • noun
  • Cloth; fabric
  • Supplies or data needed to do a certain thing
  • Substance from which a thing is made of

lithosphere

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US / ˈlɪθəsfɪə(r) /

UK / ˈlɪθəsfɪr /

A1
  • noun
  • Solid part of the earth consisting of the crust and outer mantle

state

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US / steɪt /

UK / stet /

A1
  • adjecitve
  • Concerning region within a country
  • noun
  • Region within a country, with its own government
  • Situation or condition something is in
  • verb
  • To say; declare as fact

you

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US / jʊ /

UK / ju /

A1
  • pronoun
  • Person someone is speaking or writing to
  • Person or people in general

little

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US / 'lɪtl /

UK / ˈlɪtl /

A1
  • adjecitve
  • Being short in length of time
  • Not great in size, amount, or degree; small
  • Being very young or younger than others
  • adverb
  • By an amount or degree that is not very much
  • Not often; rarely
  • noun
  • A person's name

land

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US / lænd /

UK / lænd /

A1
  • noun
  • Region or country
  • Earth; the ground
  • verb
  • To arrive or cause a boat to arrive at the shore
  • To obtain or get something that you wanted
  • To (cause to) come down to the ground safely
  • To cause to arrive in a specific place or state

water

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US / 'wɔ:tə(r) /

UK / ˈwɔtɚ, ˈwɑtɚ /

A1
  • noun
  • Clear liquid that forms the seas, rivers and rain
  • Large area such as an ocean or sea
  • verb
  • (Of the eyes) to produce tears
  • (Mouth) to become wet at the thought of nice food
  • To pour liquids onto a plant to keep it alive

well

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US / wel /

UK / wɛl /

A1
  • adjecitve
  • Being in a fortunate, good condition or state
  • Healthy and in good condition
  • adverb
  • In an acceptable, proper, or successful manner
  • In a complete, total, or full manner
  • A great and considerable degree
  • In a successful way, in a good or satisfactory way
  • exclamation
  • Used to begin or continue a particular statement
  • Used to show you want to start saying something
  • Used to express that you are waiting for a reply
  • You say this to change the topic of a conversation
  • Used to indicate you are making a final remark
  • noun
  • Long deep hole in the ground to get water
  • verb
  • To cause your eyes to fill with tears

why

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US / waɪ /

UK / hwaɪ, waɪ /

A1
  • adverb
  • Question word to ask for a reason
  • exclamation
  • (Used to express surprise or approval)

replace

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US / rɪ'pleɪs /

UK / rɪˈples /

A2
  • verb
  • To use instead of something else
  • To return an item to its original location

warm

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US / wɔ:m /

UK / wɔrm /

A1
  • adjecitve
  • Friendly, sincere and kind to others
  • Being friendly or sincere
  • Slightly hot; not very hot
  • verb
  • To become more friendly or to like something
  • To make something hotter

cool

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US / ku:l /

UK / kul /

A1
  • adjecitve
  • Steady and calm when facing difficulties
  • Almost cold; not warm or hot
  • Smart or stylish in a way (young) people admire
  • Unfriendly in an indirect way; distant
  • verb
  • To make something decrease in temperature
  • (Of an emotion, etc.) to become less strongly felt

time

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US / taɪm /

UK / taɪm /

A1
  • noun
  • Speed at which music is played; tempo
  • Point as shown on a clock, e.g. 3 p.m
  • Number of hours, minutes needed to do something
  • Occasion when something happens
  • Period or occasion that something occurred
  • Period in history or the past
  • Something measured in minutes, hours, days, etc.
  • How long an event takes; duration
  • verb
  • To check speed at which music is performed
  • To choose a specific moment to do something
  • To measure how long an event takes, e.g. a race
  • To schedule something to occur at a specific moment

lower

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US / 'ləʊə(r) /

UK / ˈlaʊɚ, laʊr /

A2
  • adjecitve
  • In a position more near the bottom
  • verb
  • To move something downward to the ground

molecule

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US / ˈmɒlɪkju:l /

UK / ˈmɑlɪˌkjul /

B2
  • noun
  • Two or more atoms chemically combined

solid

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US / 'sɒlɪd /

UK / ˈsɑlɪd /

A2
  • adjecitve
  • Being able to be trusted; reliable
  • Substance that is hard or of fixed shape
  • Being well made and expected to last long
  • Having no space or emptiness inside
  • Being made entirely of one material or substance
  • noun
  • Something firm or hard; not gas or liquid

stuff

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US / stʌf /

UK / stʌf /

A1
  • noun
  • Generic description for things, materials, objects
  • verb
  • To push material inside something, with force

cold

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US / kəʊld /

UK / kold /

A1
  • adjecitve
  • Having a very low temperature
  • Being unfriendly or lacking emotion
  • noun
  • Illness of sneezing, coughing, and a sore throat

cycle

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US / ˈsaɪkl /

UK / ˈsaɪkəl /

A2
  • noun
  • Series of regular and repeated actions
  • Bicycle, bike
  • verb
  • To go through a series of events repeatedly
  • To ride on a bicycle

just

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US / dʒʌst /

UK / dʒʌst /

A1
  • adjecitve
  • Proper or appropriate; as is deserved
  • Doing or being what is right or fair
  • Legally correct; having enough evidence
  • adverb
  • Almost; nearly
  • Exactly at the time of
  • Exactly (the same as, like)

those

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US / ðəʊz /

UK / ðoz /

A1
  • determiner
  • The people or things we are talking about
  • pronoun
  • The objects far from the speaker

combination

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US / ˌkɒmbɪ'neɪʃn /

UK / ˌkɑmbəˈneʃən /

B1
  • noun
  • Series of letters or numbers needed to open a lock
  • Act or result of mixing things together

oceanic

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US / ˌəʊʃiˈænɪk /

UK / ˌoʃiˈænɪk /

B2
  • adjecitve
  • Concerning the ocean

talk

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US / tɔ:k /

UK / tɔk /

A1
  • noun
  • Style of speaking
  • Discussion between two countries
  • Giving information in front of people; lecture
  • Saying things or ideas to someone with words
  • verb
  • To make a formal speech about something
  • To say things or ideas to someone with words

expect

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US / ɪk'spekt /

UK / ɪkˈspɛkt /

A1
  • verb
  • To believe something is probably going to happen

quite

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US / kwaɪt /

UK / kwaɪt /

A1
  • adverb
  • Not very; fairly
  • Very; In a complete or total manner

can

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US / kæn /

UK / kən,kæn /

A1
  • noun
  • A metal container for storing food
  • other
  • Able to; have the skill to; have the time to
  • verb
  • To have permission to
  • To be possible to do
  • To preserve food by sealing it in a metal container

not

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US / nɒt /

UK / nɑt /

A1
  • adverb
  • Word indicating the negative
  • (Used to form the negative of verbs)

effect

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US / ɪ'fekt /

UK / ɪˈfɛkt /

A1
  • noun
  • An advantage, benefit
  • Change brought about by a cause; result

video

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US / 'vɪdɪəʊ /

UK / ˈvɪdiˌo /

A2
  • adjecitve
  • Of a moving film, with sound
  • noun
  • Recording capturing action with sound
  • verb
  • To make a moving film of, with sound

maybe

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US / ˈmeɪbi /

UK / ˈmebi /

A1
  • adverb
  • Possibly but not certainly; perhaps

asthenosphere

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US / æs'θi:nɜ:ˌsfɪə /

UK / æs'θi:nɜ:ˌsfɪr /

A1
  • other
  • Lower layer of the crust

potentially

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US / pə'tenʃəlɪ /

UK / pəˈtɛnʃəlɪ /

B1
  • adverb
  • That could happen or become reality

would

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US / wʊd /

UK / wʊd /

A1
  • other
  • Used to indicate something imagined
  • Used to ask or request something politely
  • Verb used to indicate possibility, request etc.
  • Used to indicate a preference
  • Used to indicate a reaction
  • Indicates something that occurred repeatedly
  • Used to indicate willingness or ability to do

yet

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US / jet /

UK / jɛt /

A1
  • adverb
  • At a later time (used after ‘not’)
  • (Used to emphasize that thing is, will be greater)
  • Eventually; at a future time
  • Until now; up to the present
  • conjunction
  • Adding to what has been said, often as a contrast

rift

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US / rɪft /

UK / rɪft /

B2
  • noun
  • Opening made by splitting; a major disagreement

definitively

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US / dɪ'fɪnətɪvlɪ /

UK / dɪ'fɪnətɪvlɪ /

B2
  • adverb
  • Clearly and leaving no further question

want

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US / wɔnt /

UK / wɑnt, wɔnt /

A1
  • noun
  • Something you desire or wish for
  • State or condition of poverty
  • verb
  • To desire or wish for something; hope for a thing

same

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US / seɪm /

UK / sem /

A1
  • adjecitve
  • Being equal in quality and amount
  • Identical; not different
  • Not changing; constant

deal

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US / di:l /

UK / dil /

A1
  • verb
  • To cope with something - usually troubles
  • To give (something bad e.g. news) to
  • To buy and sell illegal drugs
  • To give out (cards, etc.) to; distribute
  • To do business with someone or to sell products

become

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US / bɪ'kʌm /

UK / bɪˈkʌm /

A1
  • verb
  • To begin to be; grow to be; develop into
  • To be suitable for a particular job or role

but

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US / bət /

UK / bʌt,bət /

A1
  • conjunction
  • Used before you say something different, opposite

now

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US / naʊ /

UK / naʊ /

A1
  • adverb
  • At the present time or moment
  • Right away or in the next possible moment
  • Used to refer to something that just happened
  • Time between the present and a moment in the past
  • conjunction
  • Resulting from or because of something

slow

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US / sləʊ /

UK / sloʊ /

A1
  • adjecitve
  • Lacking activity, busyness or excitement
  • (Clock) showing time earlier than the actual time
  • Having difficulty understanding simple things
  • Moving or happening without speed; not fast
  • verb
  • To move, with less speed than before
  • To move or go without much speed

part

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US / pɑ:t /

UK / pɑ:rt /

A1
  • adjecitve
  • To some degree; half; not fully
  • noun
  • Division of a book
  • Ratio of something, e.g. 3 of gin, 1 of tonic
  • A line in a person's hair, made with a comb
  • Character an actor plays on stage, movie, or TV
  • Some, but not all of a specific thing
  • Role in causing something to happen
  • verb
  • To make a line in a person's hair, by using a comb
  • To move two things apart creating a space
  • To leave someone, or to break off a relationship

divergent

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US / daɪ'vɜ:dʒənt /

UK / dɪˈvə:dʒənt, daɪ- /

B2
  • adjecitve
  • Moving away from another, or from a standard

away

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US / ə'weɪ /

UK / əˈwe /

A1
  • adjecitve
  • Not present
  • adverb
  • Disappear completely
  • Doing something with a lot of energy
  • Not here; far from here; in a different direction
  • To a different area, location

transfer

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US / træns'fɜ:(r) /

UK / trænsˈfɚ /

A2
  • noun
  • Moving to a different place, job, or school
  • Act of giving the right to a property to another
  • Picture that is pressed to copy it onto something
  • Use of ideas or skills in a different situation
  • Ticket allowing you to get on another plane, bus
  • verb
  • To move to a different place, job or school
  • To give someone an illness through contact
  • To give someone your right to a property
  • To move something from one place to another
  • To use ideas or skills in a different situation
  • To get off a plane, bus etc. and get on another

have

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US / həv /

UK / hæv /

A1
  • verb
  • To drink, smoke, eat or use something
  • To experience the effects of something
  • To organize an event, or join in an activity
  • To own, possess, or hold something
  • To cause to happen or produce a particular effect

process

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US / prə'ses /

UK / ˈprɑsˌɛs, ˈproˌsɛs /

A2
  • noun
  • Dealing with official forms in the way required
  • Set of changes that occur slowly and naturally
  • verb
  • To organize and use data in a computer
  • To deal with official forms in the way required
  • To prepare by treating something in a certain way
  • To adopt a set of actions that produce a result
  • To convert by putting something through a machine

low

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US / ləʊ /

UK / lo /

A1
  • adjecitve
  • Having a small quantity, supply, or amount
  • Being unhappy or unpleasant in attitude
  • Not high; being near the ground, or bottom
  • (Of a voice, sound) being soft; quiet
  • noun
  • Situation of not having a lot of something

could

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US / kəd /

UK / kʊd /

A1
  • other
  • Past form of 'can' to mean have ability
  • Used to ask for something politely, or to offer

plate

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US / pleɪt /

UK / plet /

A2
  • noun
  • Flat dish used for eating or serving food
  • Smooth, thin piece of metal applied in a layer
  • Small, flat piece of metal with information on it
  • verb
  • To put a layer of metal on something to protect it

with

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US / wɪð /

UK / wɪð, wɪθ /

A1
  • preposition
  • As an employee of a certain company
  • Against something or someone
  • By using something as a means
  • Due to; because of
  • Including
  • Possessing as a feature
  • Related to
  • (Of the manner/attitude by which you do something)
  • Used to express that people or things are together

end

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US / end /

UK / ɛnd /

A1
  • noun
  • The point where a process or activity stops
  • A point that marks the limit of something; finish
  • Goal or desired result
  • The tip, edge or limit of something
  • verb
  • To be the last part of something

see

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US / si: /

UK / si /

A1
  • verb
  • To go on a date with someone
  • To predict whether something is, or will be true
  • To understand what someone says
  • To use your eyes to look at something
  • To visit a place often for sightseeing or pleasure
  • To visit or meet with someone
  • To find out by waiting or looking
  • To watch (a game, movie or TV show)

crust

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US / krʌst /

UK / krʌst /

B2
  • noun
  • Hard outer layer of something, e.g. the earth
  • Hard crisp outer layer of bread, baked goods

remember

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US / rɪ'membə(r) /

UK / rɪˈmɛmbɚ /

A1
  • verb
  • To give someone a gift, e.g. birthday, wedding
  • To hold a thought in your mind to not forget it
  • To bring a previous image or idea to your mind

upper

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US / ˈʌpə(r) /

UK / ˈʌpɚ /

B1
  • adjecitve
  • Located above others of the same kind
  • Being the northern part of a region
  • Being closer to the source of a river
  • noun
  • Drug that improves mood or increases energy
  • Something happy or encouraging
  • Top part of a shoe, other than the flat bottom

review

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US / rɪˈvju: /

UK / rɪˈvju /

A2
  • noun
  • Examination of soldiers and supplies
  • Opinion, as in a paper, about movie, book, or play
  • Studying again to remind yourself about something
  • verb
  • To carefully look at the quality of something
  • To formally examine something in the military
  • To write an opinion about movie, book, or play
  • To study again to remind yourself about something

before

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US / bɪˈfɔ:(r) /

UK / bɪˈfɔr,-ˈfor /

A1
  • adverb
  • At a time earlier than the present; previously
  • conjunction
  • In advance of something happening
  • preposition
  • In front of someone or something

where

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US / hwɛə /

UK / hwɛr, wɛr /

A1
  • conjunction
  • At or in the place which
  • In whatever place
  • pronoun
  • Word you use to ask the location of something

hot

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US / hɒt /

UK / hɑ:t /

A1
  • adjecitve
  • Angry or excited
  • Being very good at something
  • Having a high temperature
  • Popular and causing a great deal of excitement
  • Attractive in a sexually exciting way
  • (Of food) very spicy
  • Stolen; dangerous to buy or trade in

from

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US / frəm /

UK / frʌm, frɑm,frəm /

A1
  • preposition
  • Starting at a particular place, time or level

far

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US / fɑ:(r) /

UK / fɑr /

A1
  • adjecitve
  • A long way away
  • Being a long way away
  • adverb
  • To a large degree or extent

completely

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US / kəmˈpli:tli /

UK / kəmˈpliːtli /

A1
  • adverb
  • In every way or as much as possible

form

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US / fɔ:m /

UK / fɔrm /

A1
  • noun
  • Sports team or person's current winning record
  • Document you complete when making an application
  • Visible shape or style; type; kind
  • verb
  • To organize something such as a club or group
  • To develop; to come into a shape or substance
  • To make something into a particular shape

help

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US / help /

UK / hɛlp /

A1
  • noun
  • Something given to enable a person to do something
  • Assistance given to someone in need
  • Someone who makes something easier or possible
  • verb
  • To act to enable a person to do something; assist
  • To make something better or less difficult

flame

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US / fleɪm /

UK / flem /

A2
  • noun
  • The red part you can see in fire
  • verb
  • To glow
  • To burn or glow in a fire
  • To glow (as in the sun or sunset)
  • To send angry messages over the Internet; to troll

along

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US / əˈlɒŋ /

UK / əˈlɔ:ŋ /

A1
  • adverb
  • As a companion; taken with someone
  • preposition
  • At a point on a line

particular

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US / pəˈtɪkjələ(r) /

UK / pɚˈtɪkjəlɚ, pəˈtɪk- /

B2
  • adjecitve
  • One specific (one)
  • Having firm ideas about what is desirable
  • Being special or more than is typical

back

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US / bæk /

UK / bæk /

A1
  • adjecitve
  • Farthest from the front e.g. in a classroom
  • adverb
  • Have returned to a place you were before
  • noun
  • The part of a chair that the upper body leans upon
  • Location at the rear of something
  • The reverse of side something
  • Area on the rear of your body
  • verb
  • To bet money on something
  • To go backwards in a car
  • To support and encourage someone or some cause

over

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US / 'əʊvə(r) /

UK / ˈovɚ /

A1
  • adverb
  • Finished; no longer happening
  • Towards the ground/away from a standing position
  • noun
  • A set of six consecutive balls bowled in cricket
  • other
  • Finished
  • preposition
  • Showing the relation when a thing is above another
  • On or covering something
  • Above or across something
  • More than you need
  • From one side to the other
  • In the direction of; toward

crustal

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US / 'krʌstl /

UK / 'krʌstəl /

B2
  • adjecitve
  • Of or like the crust of the earth or moon

most

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US / məʊst /

UK / most /

A1
  • adverb
  • Very; extremely
  • Greatest possible degree
  • pronoun
  • Nearly all of something

call

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US / kɔ:l /

UK / kɔl /

A1
  • noun
  • A order or request for action
  • The sound an animal makes, often when in danger
  • A correct prediction, e.g. a decision in a game
  • A short visit to a place or person
  • A decision by a referee or umpire in a game
  • verb
  • To make a request or order for action
  • (Animal) to make sounds to warn of danger
  • To announce the date of an election
  • To make a judgment about something
  • To give someone or something a name
  • To guess in advance the result or outcome
  • To visit a place or person for a short time
  • To phone someone
  • To speak, announce or shout in a loud voice

come

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US / kʌm /

UK / kʌm /

A1
  • verb
  • To arrive at a place
  • (Of mail) to be delivered
  • To move toward someone; go with someone
  • To reach a certain point or state

ridge

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US / rɪdʒ /

UK / rɪdʒ /

B1
  • noun
  • Edge where two leaning surfaces meet
  • Raised, narrow area, usually on top of a hill

something

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US / ˈsʌmθɪŋ /

UK / ˈsʌmθɪŋ /

A1
  • adverb
  • In some degree or measure
  • noun
  • a person or thing of some value or consequence
  • pronoun
  • Thing that is not yet known or named
  • Approximately

cooler

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US / ˈku:lə(r) /

UK / ˈkulɚ /

A1
  • adjecitve
  • More cool than
  • Being more smart or stylish than others
  • noun
  • A box to keep things such as food, drink cool

distance

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US / 'dɪstəns /

UK / ˈdɪstəns /

A2
  • noun
  • Lack of friendliness toward another person
  • Amount of space between two places or things
  • verb
  • To make it clear that you are not involved

think

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US / θɪŋk /

UK / θɪŋk /

A1
  • verb
  • To have an idea about something without certainty
  • To have an idea, opinion or belief about something

throughout

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US / θru:ˈaʊt /

UK / θruˈaʊt /

A2
  • adverb
  • From the beginning of something until the end
  • preposition
  • Over/across an entire place/thing; in every part

familiar

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US / fəˈmɪliə(r) /

UK / fəˈmɪljɚ /

A2
  • adjecitve
  • Well-known or easily recognized

lot

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US / lɒt /

UK / lɑt /

A1
  • noun
  • What happens to a person in life from chance; fate
  • A group of people seen together
  • Item for sale at an auction
  • Small area of land used for a purpose e.g. parking

and

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US / ənd /

UK / ənd, ən,ænd /

A1
  • conjunction
  • Used to refer to two or more things
  • Plus; in addition; on top of that
  • Used to introduce an action that follows another

only

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US / ˈəunli /

UK / ˈonli /

A1
  • adverb
  • Just one; just that amount or thing; not more than
  • Not very important or serious
  • Just that type of thing, person
  • Short time ago; not before a certain time
  • conjunction
  • Except; but

any

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US / 'enɪ /

UK / ˈɛni /

A1
  • adjecitve
  • One, or some, no matter which
  • pronoun
  • One (thing) of many; some

put

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US / pʊt /

UK / pʊt /

A1
  • phrasal verb
  • to make a light stop shining by pressing or moving a switch
  • verb
  • To move or place a thing in a particular position
  • To rate something in importance or value
  • To write or say something in a certain manner

general

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US / 'dʒenrəl /

UK / ˈdʒɛnərəl /

A1
  • adjecitve
  • Widespread, normal or usual
  • noun
  • Top ranked officer in the army

viscous

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US / ˈvɪskəs /

UK / ˈvɪskəs /

C1
  • adjecitve
  • Quality of how thick, thin, and sticky a liquid is

direction

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US / də'rekʃn /

UK / dɪˈrɛkʃən, daɪ- /

A2
  • noun
  • When someone tells people what to do
  • Describes the way you are going, e.g. North

bounce

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US / baʊns /

UK / baʊns /

B1
  • noun
  • A person's energy or confidence
  • Quality causing a person's hair to appear healthy
  • verb
  • To move around energetically, playfully
  • To forcibly remove a person from a bar, nightclub
  • (Of check) to be rejected due to inadequate funds
  • To strike a surface and rapidly change direction
  • To move energetically in an up and down motion

rocky

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US / 'rɒkɪ /

UK / ˈrɑki /

A1
  • adjecitve
  • (Of a marriage, etc.) involving many difficulties
  • With abundant rocks or stones

look

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US / lʊk /

UK / lʊk /

A1
  • noun
  • Person's beauty or physical attractiveness
  • Particular style of dress, clothes, or appearance
  • The way someone, something appears to be
  • Act of searching for or examining something
  • verb
  • To appear to be; seem

due

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US / dju: /

UK / du, dju /

A1
  • adjecitve
  • When something is required or expected
  • Owed to a person as a right
  • noun
  • Something you deserve; something you can expect

bit

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US / bɪt /

UK / bɪt /

A1
  • noun
  • Device put in a horse's mouth to control it
  • Small piece of something
  • verb
  • (E.g. of fish) to take bait and be caught

take

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US / teɪk /

UK / tek /

A1
  • noun
  • Filming of a single scene for TV or the movies
  • verb
  • To accept something that is offered
  • To use a method of traveling, e.g. a bus or train
  • To use a camera to make (a photo)
  • To pick up something and go away with it
  • To study a subject in school
  • To attempt to pass (an exam)
  • To require a certain amount of time, money, space

its

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US / ɪts /

UK / ɪts /

A1
  • adjecitve
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  • Subtitles section
  • What I want to do in this video is talk a little bit about maybe why the plates are actually moving in the first place.
  • And nothing I'm talking about in this video has been definitively proved.
  • This is just kind of the current thinking, the leading thinking, on why plates are actually moving.
  • Although we haven't seen the definitive evidence yet, and it's probably a combination of a bunch of things.
  • Now, before we even talk about plates, let's just talk about convection.
  • And you might already be familiar with the term, but just in case you're not, let's do a little bit of review of convection.
  • So let's say I have a pot over here.
  • So that is my pot.
  • And it contains some water.
  • So I have water in my pot.
  • And let's say I only heat one end of the pot.
  • So I put a flame right over at that end of the pot.
  • So what's going to happen?
  • Well, the water that's right over the flame is going to be warmed up more than any of the other water.
  • So this water is going to get warm.
  • But when it gets warm, it also becomes less dense.
  • When you have a fluid, if you warm it up, the molecules are vibrating more.
  • They have more kinetic energy.
  • They're going to a bounce further distances away from each other.
  • They will become less dense.
  • And if you have something that's less dense, and it's surrounded by things that are more dense, and we're dealing in kind of a fluid state right here, that warm, less dense water is going to move upwards.
  • It's going to move upwards.
  • Well, when it moves upwards something has to replace it.
  • So you're going to have cooler water from this side of the container kind of replacing where that water was.
  • Now, this water, as it rises, what's going to happen to it?
  • Well, it's going to cool down.
  • It's going to get further from the flame.
  • It's going to mix with maybe some of the other water, or transfer some of its kinetic energy to the neighboring water.
  • So it'll cool down.
  • But once it cools down, what's it going to want to do?
  • Remember, in general, the closer you are to the flame.
  • So the water closer to the flame in general is going to be warmer.
  • So all of this stuff is going to be warmer, and all of this stuff up here, like the coldest water, is always going to be furthest from the flame.
  • And so the coldest water is going to be over here.
  • But remember, the coldest water is also the densest water.
  • So this water over here is dense.
  • And so it will sink.
  • It's denser than the water around it.
  • And it also helps replace the water that's going here to get warmed up again.
  • And so what you do is you have this cycle here.
  • Warm water rises, moves over to the right down here, and then goes back down as it cools down, and it's dense, and then it gets warmed up again.
  • And so this process, essentially what it's doing is it's transferring the heat.
  • It's allowing the heat to be transferred from this one spot throughout the fluid.
  • And so we call this process, this is convection.
  • Now, the reason why we think the plates are moving is because we think that there are similar types of convection currents in the asthenosphere, in the mantle, in the more fluid part of the mantle.
  • Remember, most of the mantle you can kind of view it as this mooshy, spongy, not quite liquid, but not quite solid state, kind of plastic.
  • It can kind of moosh past.
  • It can kind of flow like super, super, super thick, like super viscous fluid.
  • So not quite solid, not quite liquid.
  • But the same thing could be happening.
  • You have certain areas in the mantle that are hotter than others, and this particular in the asthenosphere.
  • And those areas, that's where you're going to have the material in the mantle move up, because it's hotter, it's less dense, and it will move up.
  • And maybe it'll cause one of these divergent rifts where kind of plate material and crustal material is forming.
  • And then as it moves up, it cools down, and eventually sinks, only to get heated up again.
  • So it has this kind of circular motion just like we saw with the boiling water.
  • And so that process, remember this isn't completely liquid.
  • It is rocky.
  • So it's going to potentially be able to take other things with it.
  • It could maybe drag the crust along with it.
  • Or I should say it could drag the lithosphere along with it, not just the crust.
  • It could drag all this rigid rock up here along with it, causing it to move in that general direction.
  • So you have the drag there.
  • You could also imagine this kind of a suction effect, where, if you view it as a fluid, you have a bunch of fluid coming down here.
  • So it would kind of pull the lithosphere down at those points, and it would kind of push the lithosphere up at those points.
  • So you have these convection currents that are essentially driving it.
  • These aren't going to be super fast moving fluid convection currents, like you would expect with boiling water or with heated water.
  • These would be slow moving convection currents, but they're moving enough, and they're able to kind of put enough drag on the lithosphere to take the lithosphere along with it.
  • And so that's kind of at a high level the dominant theory as to why they're moving.
  • There's other ones that talk about maybe these lithospheric plates, they kind of thicken as they move further away from this area where the ridge is forming.
  • And if we look at this oceanic crust right over here.
  • And so over time, they're denser over here, because there's more cooled down material at these points.
  • And it's already a little bit lower because this is where a lot of the land is being created.
  • And so there's maybe some gravitational effects.
  • But the dominant effect, we think, is due to this convection in the upper mantle.