首页
财务会计
医药卫生
金融经济
考公考编
外语考试
学历提升
职称考试
建筑工程
IT考试
其他
登录
职称考试
下面有 3 篇短文,每篇短文后有 5 道题。请根据短文内容,为每题确定 1 个最佳选项。 The Hyper-X The Hyper-X (超...
下面有 3 篇短文,每篇短文后有 5 道题。请根据短文内容,为每题确定 1 个最佳选项。 The Hyper-X The Hyper-X (超...
admin
2020-12-24
45
问题
下面有 3 篇短文,每篇短文后有 5 道题。请根据短文内容,为每题确定 1 个最佳选项。
The Hyper-X
The Hyper-X (超音速飞机)recently broke the record for air-breathing jet planes when it traveled at a Hypersonic speed (超音速) of seven times the speed of sound. That’s about 5,000 miles per hour. At this speed, you’d get around the world — flying along the equator
(赤道)-in less than 5 hours.
The Hyper-X is an unmanned, experimental aircraft just 12 feet long. It achieves hypersonic speed using a special sort of engine known as a scramjet (超音速冲压式喷气发动机).
For an engine to burn fuel and produce energy, it needs oxygen. A jet engine, like those on passenger airplanes, gets oxygen from the air. A rocket engine typically goes faster but has to carry its own supply of oxygen. A scramjet engine goes as fast as a rocket, but it doesn’t have to carry its own oxygen supply.
A scramjefs special design allows it to obtain oxygen from the air that flows through the engine. And it does so without letting the fast-moving air put out the combustion flames. However, a scramjet engine works properly only at speeds greater than five times the speed of sound.
A booster rocket (助推火箭)carried the Hyper_X to an altitude of about 100,000 feet for its test flight. The aircrafts record-beating flight lasted just 11 seconds. That brief journey on March27 makes a major milestone on the way to a new breed of very, fast airplanes, says Werner J. A. Dahm of the University of Michigan in Ann Arbor. In the future, engineers predict, airplanes equipped with scramjet engines could transport cargo quickly and cheaply to the briijilk (边缘)of space. Such hypersonic jets could carry passengers anywhere in the world in just a few hours.
Out of the three experimental Hyper-X aircrafts built for NASA, only one is now left. The agency has plans for another 11-second hypersonic flight,this time at 10 times the speed of sound.
The Hyper-X broke the record because
选项
A It was the first air-breathing jet plane.
B It flew along the equator,
C It traveled at the speed of sound,
D It reached a speed of about 5,000 miles per hour,
答案
D
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/MMlQKKKQ
相关试题推荐
下面的短文有15处空白,请根据短文内容为每处空白确定1个最佳选项。 YoungAdultsWhoExerciseGetHigher...
下面的短文有15处空白,请根据短文内容为每处空白确定1个最佳选项。 YoungAdultsWhoExerciseGetHigher...
下面的短文有15处空白,请根据短文内容为每处空白确定1个最佳选项。 YoungAdultsWhoExerciseGetHigher...
下面的短文有15处空白,请根据短文内容为每处空白确定1个最佳选项。 YoungAdultsWhoExerciseGetHigher...
下面的短文有15处空白,请根据短文内容为每处空白确定1个最佳选项。 YoungAdultsWhoExerciseGetHigher...
下面的短文有15处空白,请根据短文内容为每处空白确定1个最佳选项。 YoungAdultsWhoExerciseGetHigher...
下面的短文有15处空白,请根据短文内容为每处空白确定1个最佳选项。 YoungAdultsWhoExerciseGetHigher...
下面的短文有15处空白,请根据短文内容为每处空白确定1个最佳选项。 YoungAdultsWhoExerciseGetHigher...
下面的短文有15处空白,请根据短文内容为每处空白确定1个最佳选项。 YoungAdultsWhoExerciseGetHigher...
下面的短文有5处空白,短文后有6个句子,其中5个取自短文,请根据短文内容将其分别放回原有位置,以恢复文章原貌。 Mt.DesertIs...
随机试题
A.利咽止痛 B.利尿消肿 C.行气活血 D.宣肺化痰 E.活血消肿
电子商务,通常是指在全球各地广泛的商业贸易活动中,在因特网开放的网络环境下.基于
某建筑场地进行浅层平板载荷试验,方形承压板,面积0.5m2,加载至375kPa时
偏执性人格障碍多见于( )。
大气环境影响预测时,采用直角坐标网格的布点原则是()。
品德受道德观念控制,所以有时不是自己的自觉行为。()
胃肠癌患者可出现A.血清淀粉酶升高B.血碱性磷酸酶升高C.血CEA升高D.血AFP升高E.血VCA-IgA抗体升高
对近视眼的叙述,错误的是( )A.眼球前后径过长B.近点较正视眼远C.眼的折光力过强D.平行光线聚焦于视网膜前E.可用凹透镜矫正
阴病治阳的病理基础是A:阴虚B:阳虚C:阴胜D:阳胜E:阴阳两虚
新产品开发战略具有的特征有()。A:全局性B:局部性C:系统性D:分散性E:相对稳定性