258.[答案]C. advantage.[注释]take advantage of(=make use of sth. for one's own benefit)利用：take advantage of my ignorance(利用我的无知)。

257.[答案]D. expression.[注释]expression此处意指“表情”。Appearance表示人的“仪表，外表”。

256.[答案]D. spoiled.[注释]spoiled使......扫兴: A shower of rain spoiled our day's outing.

255.[答案]A. pieced together.

　[注释]piece together拼合，拼凑;take off起飞;break away from脱离;pull out拔出;驶出;(车)减速。

254.[答案]D. emission.[注释]emission散发物，发射。exposure(to)暴露于：They believe that their health problems are the result of years of exposure to fine cotton dust.(他们认为，他们的健康问题是多年来暴露于棉花粉尘所致。)expansion膨胀，扩大;Heat causes the expansion of gas.本题译文：正如汽车的生产和使用越来越多一样，汽车的排气管的散发物内所含的有毒气体量也在增加。

253.[答案]D. scarcely.[注释]scarcely(=hardly, not quite, almost not)几乎没有。Scarcely是否定副词，类似的有：hardly, barely, rarely, seldom, little等。研究生入学考试中经常测试这类否定副词的用法。

252.[答案]A. ways.[注释]two ways of looking at every questions意指“观察每个问题的两个方面”。

251.[答案]A. scattered.[注释]scattered是scatter的过去分词，也可作形容词用，(=lying in different directions; not situated together, wide apart)分散的，散布在各处的。Separate分开的，spread传播;摊开，dismiss解雇。

250.[答案]B. scratched.[注释]scratch抓，搔。此外，有一常用习语：scratch one's head over sth.对某事迷惑不解，搔头皮。Snatch掠夺;stretch拉长，延伸，撑大;squeeze压榨，挤。

249.[答案]B. pick up[注释]pick up passages(接运旅客上车。)

　pull in(火车)进站;(船)靠岸;pull up停车;get off下车。