绿色化学的核心就是要利用化学原理从源头上消除污染，力图使所有作为原料的原子都被产品所消纳，实现“零排放”。下列符合这样的思想的是（　　）

计算：（1$\frac{3}{4}-\frac{7}{8}-\frac{7}{12}$）÷（﹣$\frac{7}{8}$）

句子配对。

①How many eggs are there?____ A. I cleaned my bedroom.

②When is your birthday?____B. It's Mocky's.

③How old is he？____C. He is 15.

④When did he visit his friend？____D. He is sleeping.

⑤Happy birthday to you!____E. The People's Park.

⑥Where did you go last week?____F. 20.

⑦What did you do yesterday？____G. Last month.

⑧Why was he so angry?____H. It's September 12th.

⑨Whose gift is it?____I. Because he didn't win the race.

⑩What is Mocky doing?____J. Thanks.