5. arrive-->arrived 6. me-->mine 7. however-->yet 8. Take-->Taking

9. when-->while 10. now,∧I: and/so

[解析] 7. Although不可以与however连用，但可以与yet连用。9. while此处表示对比。10. 两个单句间不能用逗号相隔，应该使用连词。

Key to Test 5

1. wanted--> want 2. we-->you 3. consist-->consists 4. time--> times

5. should ∧ brave: be 6. the power 7. Because-->If/When 8. study it well

9. good--> well 10. before-->after

[解析] 6. Knowledge is power：知识就是力量。 9. keep well：保持身体健康。

[解析] 6. Knowledge is power：知识就是力量。 9. keep well：保持身体健康。

Key to Test 6

1. the need 2. although-->because 3. lesson -->lessons 4. take-->spend

5. Our--> We 6. that -->what 7. have-->be 8. many--> much

9. we∧often: are 10. go ∧university: to

[解析] 1. in need of ：需要。 5. 根据句意，是"我们学生"不是"我们的学生"。

Key to Test 7

1. interested -->interesting 2. go -->going 3. they-->we 4. informations--> information 5. it-->which 6. 7. the -->a 8. at-->in 9. while--> when 10.do∧in: it

Key to Test 8

1. was used 2. therefore -->however 3. go-->went 4. retired∧his: from 5. said-->saying 6. to learn 7. much -->more 8. either-->too 9. many--> much 10. course-->courses

Key to Test 9

1. was caused 2. on-->in 3. billions -->billion 4. that-->which

5. Lucky-->Luckily 6. demand -->demanding 7. reduce∧use: the

8. or--> and 9. He-->It 10.turns-->turn

[解析] 1. caused by used plastic在句中作定语，修饰The "white pollution" problem，而The "white pollution" problem的谓语动词是is becoming...。 6. demanding that...属于分词作状语。 10. 主句中有suggest（建议）， 从句为everyone （should）turn to...。

Key to Test 10

1. it 2. interested -->interesting 3. which∧written: are 或者which written 4. difficult-->difficulty 5. As-->While 6. 7. on -->back 8. a-->the 9. ,∧you'll: and 10. a