根据对话内容，在空白处填写适当的话语（话语可能是一个句子，也可能是一个短语或一个

问题：

根据对话内容，在空白处填写适当的话语（话语可能是一个句子，也可能是一个短语或一个词）。使对话完整。

(Dan and Kate are talking about pollution.)

Dan: It is said that pollution is worse than before.

Kate: Yes,  I have noticed this.  What do you think of pollution?

Dan: It makes me a little worried.   1  ?

Kate: Me too.  I think pollution is everyone's problem and it is everyone's duty to protect environment.

Dan: Quite right! But as a teenager,  2  ?

Kate: To start with, we should start a clean-up club. We can give out ads after school to tell people how

important environment is.

Dan:   3  !Besides this, we should make people know that pollution is the biggest challenge that they are

facing.

Kate: I agree with you.  If everyone can do something to keep our environment clean, our world will be

  4  .

Dan: Yes. As the saying goes. One finger cannot lift a small stone.

Dan: What else?

Kate: We shouldn't throw   5   everywhere, either.

Dan: OK.  I'm sure we will be successful.