13.

She will tell us why she feels so strongly that each of us has a role _________ in making the earth a better place to live.　　　　

A. to have played　　 B. to play　　　 C. to be played　　　 D. to be playing

[解析]　 have a role to do sth.具有做某事的作用。答案为B。

12.

Unless_________ to speak ,you should remain silent at the conference.

A.invited　　　 B.inviting　　　 C.being invited　　　 D.having invited　

[解析]　 Unless you are invited to speak,you should remain silent at the conference此主从复合句省略从句的主语和助动词变为简单句：Unless invited to speak，……。答案为A。

11.

_________ the meeting himself gave them a great deal of encouragement.

A. The president will attend　　 B. The president to attend

C. The president attended　 　　　D. The president's attending

[解析]　 B项不定式的复合结构应为for sb to do sth，但不能作主语。D项是现在分词复合结构在句子中作主语。答案为D。

10.

Friendship is like money : easier made than_________.

A. kept　　 B. to be kept　　　 　C. keeping　　　 D. being kept

[解析]　 西方谚语中，常用单词的相同形式进行表达，made和kept都是过去分词，表示被动。答案为A。　

8.

The manager,_________his factory's products were poor in quality, decided to give his workers further training.

A. knowing　　 　B. known　　　　 　C. to know　　　 　D. being known

[解析]　 变为定语从句应为“The manager, who knew his factor's products were poor in quality…”know为主动，排除B、D。定语从句变为短语应用分词短语来表示。答案为A。　 9.(

The man we followed suddenly stopped and looked as if _________whether he was going in the right direction.

A. seeing　　 B. having seen　　　 C. to have seen　　 D. to see

[解析]　 原句应为“…and looked as if he was seeing whether he was…”化为简单句就变成“…looked as if to see…”。答案为D。

7.

-Why did you go back to the shop?

-I left my friend _________ there.

A. waiting　　　 B. to wait　　　 C. wait　　　　 D. waits

[解析]　 leave sb doing使某人处于某种状态，这一动作持续一段时间。D排除，因此处应用非谓语动词；B、C无持续状态的意思。答案为A。

6.

Mr Smith,_________ of the_________ speech,started to read a novel.　　　　

A. tired; boring　　 B. tiring; bored　　 C. tired; bored　　　 D. tiring; boring

[解析]　 tired of“感到厌倦”，过去分词作状语，常用来形容人；boring“令人厌烦的”，形容词，常用来形容物。所以其中状语可分解为：Mr Smith was tired of the speech.The speech was boring。译文：听烦了乏味的演讲，Mr Smith读起了小说。答案为A。　

5. An army spokesman stressed that all the soldiers had been ordered _________ clear warnings before firing any shots.

A. to issue　　　 B. being issued　　 　　C. to have issued　　　 D. to be issued

[解析]　 order后应接不定式，即order sb to do sth，因此B被排除。又因为issue clear warnings(发出明显警告)的主语是all the soldiers，也就是说all the soldiers是issue的施动者，所以issue要用主动形式，D也被排除。而且句子也没有强调动作对现在造成的影响，不必用完成时态，答案为A。

21.

-Will you stay for lunch?

-Sorry, ________. My brother is coming to see me.

A. I mustn't　　 B. I can't　　　 C. I needn't　 D. I won't

[解析]　 问句虽然用Will提问，但不能用I won't回答，这样回答使语气生硬，不符合英语习惯。用I can't 语气委婉，表示我愿意留下来吃午饭，但是由于兄弟要来而不能留下来。I mustn't 表示禁止；I needn't表示“我没必要”。答案为B。　

20.

Sorry I'm late. I　 ________　 have turned off the alarm clock and gone back to sleep again.

A. might　　　 B. should　　　　 C. can　　　 D. will

[解析]　 might have done sth.的意思是“(过去)可能做某事”，表推测；should have done sth.的意思是“本不应该做某事”，表责备。从句子的意思可知，可能当时把闹钟关上了，而不是本来不应该把闹钟关上。答案为A。