根据短文内容选词填空。(Choose the right words to fill in the blanks．)

Damage to the ozone layer

　　The writers tell us that‘ozone is a gas 　　1　　 occurs 20－50 km above the ground．It forms an essential protective layer around the earth．　　2　　 it, the sun would burn us up．’

　　We are making holes in the ozone layer mainly by using chemicals 　　3　　CFCs．We use these in fridges and spray cans, and to make plastic items such as fast food boxes．

Destruction of the rain forests

　　The burning and cutting down of trees is making the Greenhouse Effect 　　4　　 because trees take in CO₂．It also causes erosion of the soil and flooding, as 　　5　　 as destroying the people and animals who make the forests their home．

Bad habits

　　Many of our habits cause pollution, especially our habit of using things 　　6　　 and then throwing them away．This creates massive mountains of rubbish．We don't know 　　7　　 to do with the rubbish and it pollutes our land and sea．For example, seven billion drink cans are thrown away in Britain each year．That is 　　8　　 to reach from the earth to the moon．

How can we save the earth?

　　This book's idea is that we should become 　　9　　 consumers．That is, we should only buy and use things that do not damage the environment．And we should buy only from companies 　　10　　 do not damage the environment either．

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

6．________　7．________　8．________　9．________　10．________