A: Where do you 1．?
B: I 2． 3． a city.
A: Is your city clean now?
B: No, it isn't.
A: What makes the air dirty?
B: 4． makes the air dirty.
A: What can we do to 5． the city clean?
B: We can move some 6． away from our city. We can also 7． more trees. Do you like 8． trees.
C: Of course, I do. It's interesting.
搜索
