Lingling:After our lesson on the environment,'m worried about the future. Pollution is
our great enemy, and we have to fight it. If therivers are polluted, farmers can’t use
water for their crops.
Tony: And in some places, pollution fromfactories spreads over cities and villages. Itmakes people ill, and may even kills them.Pollution is a danger to our health.
Betty: And there're so many cars on the road.

They use so much oil and cause pollution aswell.
Daming: But we are only students. We can't doanything about factories and cars.
Betty: It's no use talking about things we can'tdo. We've got to think of things we can do!Daming: Such as...?
Lingling: Do you think we can make our schoola green school?
Daming: What's a green school?
Lingling: At a green school, every class collects