首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
There are two main things that make aircraft engineering difficult: the need to make every component as reliable as possible and
There are two main things that make aircraft engineering difficult: the need to make every component as reliable as possible and
admin
2014-04-23
39
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 two main requirements of aircraft design are______.
选项
A、ability to stay up in the air and ability to avoid breakdowns
B、making things both light and dependable
C、reliability and passenger comfort
D、speed and inexpensiveness
答案
B
解析
本题问飞机设计时的两个主要要求是什么。文章第一段指出,飞机制造工程面临两个主要难题:一是要把每个部件都做得尽可能可靠,二是尽可能减轻每个部件的重量。飞机一旦到达空中,如若发生故障也不可能停下来,所以,飞机的性能要绝对可靠,这也许是个生死攸关的事情。因此,本题的正确答案应是B“飞机上的部件要重量轻且可靠性强”。
转载请注明原文地址:https://kaotiyun.com/show/DnWO777K
0
在职攻硕英语联考
相关试题推荐
Hadtheexplosionbrokenout,thepassengersintheplaneshouldhavebeenkilled,foritwas______timedwiththeplane’stake-o
Withinhoursofappearingontelevisiontoannouncetheendofconscription,PresidentJacquesChiracmovedquicklytopreventa
HowtoGetPreservedasaFossil【M1】Unfortunatelythechangesofanyanimalbecomeafossilarenotverygreat,and【M2】the
TheinfluenceofthemoralstandardsofthehomeisevidentIfthereisnorecognitionofthedifference【C1】______rightandwron
Effortstoreachtheinjuredmenhavebeen______becauseofasuddendeteriorationinweatherconditions.
Standardusageincludesthosewordsandexpressionsunderstood,used,andacceptedbyamajorityofthespeakersofalanguagei
TheMITSloanSchoolofManagementstronglybelievesthatitspurposeistogivestudentsthetoolstheywillneedtobeeffecti
Theoriesaccountingforthephysicalprocessofcolorvisionhaveundergonemanychangessince1801,whenThomasYoungfirstsug
Plantsaresubjecttoattachandinfectionbyaremarkablevarietyofsymbioticallyspeciesandhaveevolvedadiversearrayof
随机试题
男性,50岁,有高血压病史5年,近期未按时服药,近日出现头痛,烦躁,心悸多汗,面色苍白,视物模糊,测血压为230/130mmHg。该患者以上临床表现产生的主要原因是
治疗气阴两伤证,宜选用的药物是
A、甾体皂苷B、三萜皂苷C、酯皂苷D、含羰基的甾体皂苷元E、含羧基的三萜皂苷元能被中性乙酸铅沉淀的是
给患者静脉注射一单室模型药物,剂量100mg,按一级动力学消除。测的不同时刻给药浓度数据如下表,外推出浓度为12μg/ml。A.1.00B.0.693C.5.21D.27.71E.3.61该药的半衰期为(
夹套管道系统中,夹套管的外管主要有()。
某高校社会工作专业师生到彝族村落参与乡村振兴工作。为获得对该村“集体性”问题的认识,掌握村落情况,他们向政府借阅了《彝族村落历史地理和自然资源》,查看了该村近年经济发展状况的数据资料;深入村民家中访问,与村民开座谈会,掌握了大量一手资料,为开展服务提供了依
已知空间直角坐标与球坐标的变换公式为(ρ≥0,-π<φ≤π,),则在球坐标系中,θ=表示的图形是()。
若一个行政行为的主体、内容、程序均合法,则该行政行为合法。()
敏感性分析(对外经济贸易大学2014真题)
Herearesomemanagementtoolsthatcanbeusedtohelpyouleadapurposefullife.1.UseYourResourcesWisely.Yourdecisi
最新回复
(
0
)