181. He has left his book here on _____, so that you can read it.
A. purpose    B. intention    C. aim    D. meaning

[答案]A. purpose.

[注释]on purpose是介词习语，意为“故意地”。如用intention,则应说by intention故意地。

182. The magician picked several persons from the audience and asked them to  help him with the performance.
A. by accident    B. on occasion 

C. at random      D. on an average

[答案]C. at random.

[注释]at random(=without aim or purpose)随便地，胡乱地：His clothes were scattered about the room at random.
By accident意外地；on occasion偶尔；on an average平均计算。

183. The open university was started in order to help those who _____ having a university education when they were young.
A. stopped    B. failed    C. missed    D. ceased

[答案]C. missed.

[注释]miss doing sth.没有做某事：I missed seeing the film when it was shown at school.(学校放映那部电影时，我没有能去看。)

184. His _____of the aeroplane was correct in every detail and could really fly.
A. shape    B. pattern    C. design    D. model

[答案]D. model.

[注释]model此句中意为“（飞机的）模型”。

185. If you _____ your demand, then maybe you will have more chance of   getting what you want.
A. conduct    B. dismiss    C. grant    D. moderate

[答案]D. moderate.

[注释]moderate(=make or become less violent or extreme)节制，缓和，减轻。

186. Don't _____ the news to the public until we give you the go-ahead (许可，准许).
A. release    B. discard    C. relieve    D. retain

[答案]A, release.

[注释]release(=allow news to be published)发布（新闻）：Details of the scheme have not yet been released to the public.(这项计划的细节尚未向公众发布。)relieve 1)减轻（痛苦，紧张情绪等）：What will relieve a headache? This will help to relieve our hardship. 2)使放心，使宽慰：The good news relieved us, for we had been very anxious. 3)赈济，救济：The fund is for relieving distress among the flood victims. 4)relieve...from(of)解除，免除； a. This medicine will help to relieve you from your pain. b. He was relieved of his (= keep; continue to have or hold)保持，继续保有：1)She retains a clear memory of her schooldays. 2)You must retain your tickets.

187. The storm sweeping over this area now is sure to cause _____ of   vegetables in the coming days.
A. rarity   B. scarcity  C. invalidity  D. variety

[答案]B. scarcity.

[注释]scarcity(=the state of being scarce)缺乏；不足（指原本充足之物暂时在数量上的缺乏）。例如：The scarcity of fruit was caused by the drought.(水果的供应不足是干旱所引起的。)rarity(=sth. uncommon, unusual or sth. valued because rare)珍稀，稀少：Snow is a rarity around the equator.(雪在赤道周围是罕见之物。)invalidity(=making weak by illness; not suitable for use)无效性，丧失工作能力。Variety(=difference of condition or quality)变化，多样化。

本题译文：目前席卷这一地区的暴风雨今后肯定会引起蔬菜短缺。

188. Jack almost fell off the cliff, but managed to _____ until help came.
A. keep on   B. catch on  C. count on    D. hang on

[答案]D. hang on.

[注释]hang on(=hold fast, keep hold)牢牢抓住，抓紧不放：Help! I can't hang on much longer.(救命啊！我支持不住啦。)keep on(doing sth.)继续（做......）；catch on 理解；count on 指望，依赖。

本题译文：杰克差点从悬崖上掉下来，但得以抓住不放直到得救。

189. Experts say walking is one of the best ways for a person to _____ healthy.
A. preserve    B. stay    C. maintain    D. reserve

[答案]B. stay.

[注释]preserve, stay, maintain, reserve这4个词均有“保持”，“维持”之意。stay后可接形容词作表语：The weather stayed wet for three days.其他3个词均为及物动词。Preserve(=keep safe from decay, risk, harm, danger, going bad etc.)保存，保护：1)Policemen preserve order in the streets.(警察在街上维持秩序。) 2)We must preserve our natural resources.(我们必须保护自然资源。)3)You paint woodwork to preserve it.(你油漆木制品以防腐烂。)Maintain(=keep up)保持，维持，维修。Reserve(=keep for a special purpose; store)保留，预定：1)I'll reserve my opinion at his time,(这时我将保留我的看法。) 2)I'll phone up today and reserve a room.(我今天将打电话预定一个房间。)

本题译文：专家们说，步行是一个人保持健康的最好方法之一。

190. Expected noises are usually more _____ than unexpected ones of the like   magnitude.
A. manageable    B. controllable
C. tolerable         D. perceivable

[答案]C. tolerable.

[注释]tolerable(=fairly good, not too bad)可忍受的：The pain has become tolerable. manageable可处理的；可管理的；controllable可控制的；perceivable可觉察的。

本题译文：料想到的嗓音通常情况下比起等量的意外嗓音来说是可以忍受的。