根据对话内容，从对话后的选项中选出能填入空白入的最佳选项，并将答案填写在本题下面的横线上。选项中有两项多余选项。

　　－David, have you noticed that our living environment is becoming more and more polluted and that animals’ natural habitats are destroyed?

　　－Yes．　　1　　 And our natural resources won’t be able to satisfy the needs of future generations．

　　－That’s it．David, as members of the Students’ Union, we have to do something about it!　　2　　．

　　－Yes, I know them：Reduce, Recycle and Reuse．　　3　　．

　　－That’s right．You know, as individuals, we can only do a few things, but if the whole university joins, that would be great．　　4　　．

　　－OK．Let’s discuss the details of it．

　　－　　5　　．

A．Let’s invite some environmentalists to give a lecture to promote the importance of the three Rs!

B．Oh, you really are a man of action．

C．Don’t worry about that．

D．Have you heard of the three Rs?

E．The person who destroys the environment should be punished．

F．If we human beings don’t stop our destructive actions, more and more species will die out in the near frture．

G．Reduce energy consumption, recycle paper, plastics, bottles and glass, and reuse paper, and other materials．

1．________　2．________　3．________　4．________　5．________