Unit 15 We’re trying to save the manatees!
a. uses b. is used c. was used d. is using
4. —it’s raining! when did it start?
—i don’t know exactly. in fact, it all this afternoon. （北京）
a. lasts b. has lasted c. lasted d. will last
5. —did you hear that water in tai lake smelt terrible?
—yes. in fact, it . that’s all because of the people and the factories around. （湖北黄冈）
a. polluted b. was polluted c. has polluted d. will pollute
参考答案：1~5 cabbb
