There are two main things that make aircraft engineering difficult: the need to make every component as reliable as possible and

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问题     There are two main things that make aircraft engineering difficult: the need to make every component as reliable as possible and the need to build everything as light as possible. The fact that an aeroplane is up in the air and cannot stop if anything goes wrong makes it perhaps a matter of life or death that its performance is absolutely dependable.
    Given a certain power of engine, and consequently a certain fuel consumption, there is a practical limit to the total weight of aircraft that can be made to fly. Out of that weight as much as possible is wanted for fuel, radio navigational (航行的,航运的) instruments, passenger seats, or freight (货物) room, and, of course, the passengers or freight themselves. So the structure of the aircraft has to be as small and light as safety and efficiency will allow. The designer must calculate the normal load that each part will bear. This specialist is called the "stress man". He takes account of any unusual stress that may be put on the part as a precaution (预防, 预防措施) against errors in manufacture, accidental damage, etc.
    The stress man’s calculations go to the designer of the part, and he must make it as strong as the stress man says is necessary. One or two samples are always tested to prove that they are as strong as the designer intended. Each separate part is tested, then a whole assembly—for example, a complete wing, and finally the whole aeroplane. When a new type of aeroplane is being made, normally only one of the first three made will be flown. Two will be destroyed on the ground in structural tests. The third one will be tested in the air.
The stress man’s job is to calculate______.

选项 A、the amount of luggage each passenger may carry
B、what height the plane will fly at
C、how strong each part must be
D、how safe the plane is

答案C

解析 本题是一道具体细节题。问压力师的工作是计算什么。利用查阅式阅读法,我们可以在文章的第二段最后几句话中找到答案。这部分指出,设计师必须计算每个部件将承受的正常负荷,这方面的专家被称为压力师,他把任何加给部件的非正常受力均纳入计算之列,以防止制造过程中的失误及意外事件所造成的损坏等。因此,本题的正确答案应是C“计算飞机每一部分需要有多大的承受力”。
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