题目内容：

We're trees. We've lived on the earth with you for thousands of years. Each day we give out oxygen and make air fresh. We can cool the air _____ you don't feel hot all the time; We help to ___ the soil（土壤）from being  washed ____ . We give all kinds of fruits and wood to you. We are your friends. But you've never been interested in us, or pay any attention to us, so you hardly know _____about us.

We are now in great danger because of you humans. You're destroying us _____ a terrible speed. You're burning and cutting down millions of us each year. Every day one tree is  ___but 30 trees are cut down. What would you do ____ all of us died? Without us, you  wouldn't get the ingredients for some of your important medicine, you wouldn't have enough  material for buildings, furniture, ____ products. Therefore, air pollution and noise pollution would become more and more______·

The best thing for you to do now is to stop destroying us and start protecting the environment, because we are the best fighters ______pollution!

1.A. because of    B. as soon as    C. even though    D. so that

2.A. support    B. operate    C. prevent    D. produce

3.A. away    B. below    C. around    D. back

4.A. anything    B. something    C. nothing    D. everything

5.A. in    B. for    C. at    D. on

6.A. built    B. lost    C. dropped    D. planted

7.A. before    B. unless    C. if    D. whether

8.A. flower    B. paper    C. water    D. glass

9.A. unfair    B. serious    C. seriously    D. kindly

10.A. through    B. across    C. against    D. except