A: What are you reading, Jill?
B: It's a book about the future.
A: Sounds cool.So 1. ______ will the future be like?
B: Well, cities will be more crowded and polluted.There will be 2. ______ trees and the environment will be in great danger.
A: That sounds bad! What 3. ______？
B: People will have less space to live in.
A: Will we have to move to 4. ______ planets?
B: Maybe. But I want to live on the earth.
A: Me too. Then what can we do?
B: We can use less water and plant more trees.Everyone should 5. ______ a part in saving the earth.