______ is a sum of money that is paid some time before you get the thing you want to buy.

• advance payment

• calculate

• challenge

• climate change

______ is to discover an amount or number using mathematics.

• challenge

• calculate

• dependence

• destruction

______ is something that is difficult and that tests someone's ability or determination.

• fresh air

• challenge

• switch to

• rising sea levels

_____ is the way the Earth's weather is changing.

• drawback

• climate change

• endangered

• estimate the cost

​ (a)   on is when you ​ (b)   someone or something in ​ (c)   to exist or continue as ​ (d)   .

• dependence
• need
• order
• before

Match the following words with their definitions

• produce, provide something

• sceptical

• a problem or disadvantage

• drawback

• doubting

• yield

• concentrate

• destruction

• when something is destroyed

• focus

​ (a)   is a type of ​ (b)   or plant that ​ (c)   may not​ (d)   because there are very few now​ (e)   .

• endangered species
• animal
• soon
• exist
• alive

_______ is to use any information that you have to guess how much something will cost.

• estimate the cost

• focus on

• fossil fuels

• fresh air

______ is to give a lot of attention to one particular subject or thing.

• infrastructure

• harness energy

• focus on

• zero emissions

______ are fuels such as coal or oil that are obtained from under the ground.

• scenery

• fossil fuels

• fresh air

• harness energy