17 Match the words with their definitions.
1 survival a something that is needed in order for something else to happen
2 challenge b the state of continuing to live or exist, even in face of difficult conditions
3 species c the scientific theory according to which plants and animals change gradually over long periods of time to become more suitable for their environment
4 requirement d a living thing, often imaginary', that is sometimes strange or frightening
5 evolution e a plant or animal group that shares similar general features
6 creature f something that needs a lot of skill, energy and determination to achieve
1 survival a something that is needed in order for something else to happen
2 challenge b the state of continuing to live or exist, even in face of difficult conditions
3 species c the scientific theory according to which plants and animals change gradually over long periods of time to become more suitable for their environment
4 requirement d a living thing, often imaginary', that is sometimes strange or frightening
5 evolution e a plant or animal group that shares similar general features
6 creature f something that needs a lot of skill, energy and determination to achieve