Complete IELTS 5-6,5// unit 5

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

to discover an amount or number using mathematics

Answer explanation

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

the way the Earth's weather is changing

when you need someone or something in order to exist or continue as before

when something is destroyed

a problem or disadvantage

a type of animal or plant that soon may not exist because there are very few now alive

to give a lot of attention to one particular subject or thing

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