语法选择

阅读下面短文，按照句子结构的语法性和上下文连贯的要求，从各题所给的A、B、C和D项中选出最佳选项。

　　It's very important that we all recycle(再利用)．In nature, everything 　　1　　 again．For example, when an animal dies, it becomes 　　2　　 animal's food．Nothing is wasted．But humans have created things like plastic bags 　　3　　 can't be broken down by nature．Our rubbish kills animals and 　　4　　 water and soil．　　5　　 we continue making too much rubbish, the problem will only get worse．If nature can't reuse the rubbish, we must recycle 　　6　　．

　　We should clean up the rubbish we've made because nature can't．

　　Recycling is also the right thing to do for another reason．The earth is rich in natural materials like water and trees, 　　7　　 these materials are not endless．We use up our natural materials much 　　8　　 than the earth is able to reproduce them．For example, each year we cut 　　9　　 more that 6,000 square miles of forest．But it takes an average of 25 years for a new tree 　　10　　．

　　Recycling can help us save the earth, so let's take action right now．

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)