248.[答案]B. unique。[注释]unique(某一类中)独一无二的。如选unusual(不寻常的，独特的)，虽然也说得过去，但毫无疑问，unique是最佳选择，因为它的后面the only one相呼应。Special专门的，专用的，例如;They went to London on a special train.[他们搭一班专车(或加班车)去伦敦。]rare稀有的，罕见的，如：rare metals(稀有的金属)。Singular单数的。

247.[答案]A. vital。

　[注释]vital 极其重要的。本题译文：在航空航天装置中必要的动力设备的重量问题是至关紧要的。

246.[答案]B. view。[注释]view在本句中意指“看，眺望”，如：It is a large room with a view of the doctor's well-kept garden. (这是一间大房间，从房间里能看到医生精心管理的花园。)本题译文：坐在汽车的前排座位可以清楚地看到乡间的景色。

245.[答案]B. trusted。[注释]trust sb. with sth. 把某事托付给某人：I can't trust him with my car.(我不能把我的车托付给他。)本题译文：你认为不会把真正有责任的工作托付给你。

244.[答案]C. tip。[注释]tip 本题中意为“小费”。

243.[答案]C. right。[注释]put sth. /sb. right 纠正;治好，使恢复健康：Since man has done so much damage, it is up to man to put the matters right. (既然人类已造成了如此巨大的损害，人类又哲人纠正这种状况。)又如：This medicine will soon put you right. (这药很快会使你恢复健康。)其他3个选择均不能与put 构成习语，故不能入选。本题译文：病人相信医生清楚地知道怎样治好他的病。

242.[答案]A. in turn。[注释]in turn (插入语)转而，依次，而又：We need revision of estimated sales and this, in turn , will mean revision in production schedule. (我们必须修改预计销量，而这反过来又意为这修订生产计划。)in return 作为报答: I wish I could do something for you in return. (我要是能为你做点事作为报案就好了。)I gave him a present but he gave me nothing in return.(我送给他一份礼物，可他却什么也不给我作为答谢。)by chance (=by accident)偶然地;无意中：I meet him by chance on Fifth Avenue.(我偶然在第5大街上遇到他。)by turns 轮流地，依次：There were twelve of us in the boat and we rowed by turns.(船上有12人，我们轮流划船。)

　本题译文：紧张的环境会导致诸如不良的饮食习惯等不健康行为，而后者又会增加患心脏病的危险。

241.[答案]A. unexpectedly.[注释]unexpectedly 出乎意料地。例如：He unexpectedly failed to get the job.(他出乎意料没有得到这件工作。)又如：We met each other unexpectedly. (我们不期而遇。)deliberately故意地：I believe the house was deliberately set fire to.(我相信这房子是有人故意放火烧的。)reluctantly 不情愿地，勉强地：She agreed, very reluctantly, to help. (她十分买鸟枪地同意帮忙。) subsequently后来，随后：He escaped from prison but was subsequently recaptured. (他越狱逃跑了，但后来又被抓回来。)

　本题译文：马戏团地老虎虽然已被驯服，但也会出乎意料地袭击驯兽师。

240.[答案]A. state.[注释]state n. 状况，状态。例如：She is in a poor state of health. Situation处境，形势，局面，情况，工作：He was in a hopeless situation. condition 情况(多用复数)： Economic conditions were bad. occasion 场合，时机。

239.[答案]B. in no time.[注释]in no time (=in a very little time, soon, quickly)立即，马上：The bus filled with students in no time. (这辆公共汽车很快就被学生挤满了。)