221. Professor Jordon is well known for his _____ into the habits of the common housefly.

　 A. examination　　 B. introduction

　 C. research 　　　D. expression

[答案]C. research

[注释]research into对...研究：1)(作动词用)He is researching into the reading problems of young school children.2)(作名词用)to carry out a research(=some research)into the causes of brain damage.(对大脑损伤原因进行研究)。

研究可译为make researches into, make a study of 或直接用动词study vt或research into (a problem etc.).

220. I support your decision, but I should also make it clear that I am not going to be _____ to it.

A. connected　　 B. fastened　　 C. bound　　 D. stuck

[答案]C. bound

[注释]be bound to sth.受...的约束：I was bound to my promise.(我受我的诺言约束)[注意]be bound to do sth.1)一定会：The plan is bound to win.(这项计划一定会成功。)2)有责任(义务)：You are bound to obey the laws.(你有责任遵守法纪)。

本题译文：我支持你的决定，但是我得说明，我不打算受它约束。

219. John _____ knowledge of radio just by staying around the radio station.

A. caught on　 B. worked up　 C. took up　 D. picked up

[答案]D. picked up

[注释]pick up学到，习得。详见Ⅲ。130注释。

218. In spite of the thunderstorm, the children slept _____ all night.

A. densely　　 B. soundly　　 C. loudly　　 D. noisily

[答案]B. soundly

[注释]sleep soundly熟睡。也可以说sleep heavily.

217. They did not find _____ to prepare for the worst conditions they might meet.

　 A. worth their while　　 B. it worthwhile

　 C. it worth 　　　　　　D. it worthy

[答案]B. it worthwhile

[注释]worthwhile值花时间(或精力)干的：1)The visit to Paris was worthwhile .2)He thinks teaching foreign languages is worthwhile.3)She has a very worthwhile job.4)I think it worthwhile to work on my stamp collection.

Worthy (of)配得上，值得：1)He is worthy of being praised.(=He is worthy to be praised.)2)He is a worthy winner.3)She is not worthy to talk to man like you.(她配不上与你这样一位男士谈话)。

216. The microphone enabled them to keep in touch, in other words, it made it _____ for them to contact each other.

A. likely　　 B. capable　　 C. possible　　 D. probable

[答案]C. possible

[注释]able有才能的，有能力的，指人的才智，而且是受过实际锻炼的才干。Capable“有才能的，能胜任的”(有褒、贬 二义)，如：He is capable of anything.(他什么事都干得出来。)此句含有明显得贬义。此外，作表语时，able接不定式，capable接of. capable还有一意思是“有可能 的”，例如：The car is capable of being repaired .(这辆汽车是有可能修好的。)用于此义时，be capable of 后常接被动语态动名词或有动作意义的名词：The situation is capable of improvement .possible 强调客观可能性，“可能的”程度比probable"大概的，很可能的低一些。

[注意]likely与possible在结构搭配上的区别。Likely可用于下列句型中：1)It is likely that...例如：It is highly likely that he will succeed.(很可能他会成功。)2)think(feel, consider)it likely ...例如：I think it likely that we will ultimately get a certain amount of money.3)be likely to do sth.例如：He is likely to see you again .但下面的句型是错误的，It is likely for sb to do sth.所以think it likely for sb. to do sth.也是错误的，故本题不能选likely.

215. She is making herself ill with _____ over her son's future.

A. trouble　　 B. annoyance　　 C. disgust　　 D. worry

[答案]D. worry

[注释]worry既可作动词用，也可以作名词用，意思是“忧虑”，后接介词about或over。worry over 比worry about对某事的忧虑更为持久，更为专注，如：He worries over the least thing that goes wrong.(他总是惟恐有一点小事出错。)

214. When products made in factories _____, they are thrown away as garbage.

　 A. come to an end　　 B. are put to use

　 C. are used up 　　　D. wear out

[答案]D. wear out.

[注释]wear out本题中意指(become useless form continued use of wear)用坏，穿破，如：The machine will soon wear out.(这机器即将用坏。)come to and end(结束)，put ... to use(投入使用), use up(用完)， come into use(开始投入使用)。

213. I _____ her not to walk on the thin ice but she would not listen to me.

A. warned　　 B. persuaded　　 C. suggested　　 D. noticed

[答案]A. warned.

[注释]warn sb. (not) to do sth.警告某人(不)做某事。

Suggest不能接sb. to do sth。persuade sb.(not) to do sth.说服、某人(不)做某事；本题中不能选D. persuaded, 因该动词强调行为的结果。从逻辑上讲，既然“说服了”，那么与she wouldn't listen to me就前后矛盾了。如果把句子该为：I tried to persuade her not to walk on the thin ice but she wouldn't listen to me.(我极力劝她不要在薄冰上走，但她不愿听我的话。)，那么就符合逻辑了。

[注意]warn sb. of sth.警告某人有......。

212. It was clear that the small grocer was _____ people he owed money to.

　 A. at the expense of 　　B. at the risk of

　 C. in the way of 　　　　D. at the mercy of

[答案]D. at the mercy of.

[注释]at the mercy of在......支配下：The ship was at the mercy of the waves.(这艘船任凭风浪摆布。)

at the expense of以......为代价，靠牺牲......；in the way of碍......事；at the risk of冒......的危险：1)He devoted his time to football at the expense of his studies.(他牺牲学习把时间都花在足球上。) 2)Her social lift got in the way of her studies.(她的社交生活妨碍了她的学习。) 3)We do this at the risk of our lives and liberties.(我们冒丢掉生命和丧失自由的危险做这件事。)

本题译文：显然，这家小杂铺任凭其债主的摆布。