1 . 听下面一段对话，补全句子。
M: Meat production is one of the worst things for the environment. People cut down ancient forests to     1     cows, just to produce hamburgers!
W: Yes. I don’t eat meat at all, because I don’t want to     2     innocent creatures.

2 . 听下面一段对话，补全句子。
W: You must remember to take away all your litter after you     1     in the countryside. It looks so unpleasant when people leave rubbish everywhere.
M: Yes, and I read it can be       2    to the animals who live in this habitat.

3 . 听下面一段对话，补全句子。
W: Plastic is a huge problem for the earth. It takes hundreds of years to       1    .
M: I agree, but it’s unrealistic for us to live without it. It is     2     so many things.
W: Well, in the future, I hope we can find a better substance.