2. 它不僅成本低廉且?guī)缀醪划a(chǎn)生污染。

四、完成句子

1. 他們將如何處理舊衣服呢？

5. 大自然是我們的財富。我們依賴其豐富的資源生存。

Nature is our treasure.                     

4. 記住每個人都可以做點有益的事！

8. He won’t get there on time if he (not leave) earlier tomorrow.

7. (make) sure that there are no mistakes,you must be more careful with your homework.

6. Until your passport (show) to us,we won’t let you in at all.

5. —How do you like the city?

  —Wonderful!I (stay) here for another two years.

4. —Why didn't you stop him going out?

  —Sorry,but I (write) a letter and didn't notice him go out.

3. All the food (eat) up,but they still felt hungry.