Study the examples of conditionals in the visitor’s guide. Choose the correct verb forms.

EARTH – A VISITOR’S GUIDE

- Welcome to Earth! We’re between the planets Venus and Mars.

- To survive, humans need food and water – but if we (1) eat / eaten too much food, we become ill.

- Most plants here need water, food and light. If you keep a plant in the dark, it (2) won’t / wouldn’t grow.

- We love being outside in the sun, but if we don’t use special protection, our skin (3) burns / burnt!

- We’re friendly, but people here can be selfish. If we (4) share / shared things more, it would be a better place.

- There are a lot of us here. If our population (5) grows / grew more, we’ll need a new place to live.

- A lot of other species are near extinction. If we don’t protect them, (6) they’ll / they’d be disappear.