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
47
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.
Which of the following is NOT true of the scramjet engine?
选项
A It has been used on passenger planes
B The air it breathes does not put out the combustion flames.
C It works at speeds greater than five times the speed of sound
D It goes as fast as a rocket.
答案
A
解析
转载请注明原文地址:https://ti.zuoweng.com/ti/pMlQKKKQ
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...
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...
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
关于脑膜炎奈瑟菌,正确的是 A.消化道传播 B.泌尿生殖道传播 C.生存能
因被代理人对代理人授权不明确,给第三人造成损失,关于损失承担的说法,正确的是(
事业心和责任感是个人敬业、勤业、履行职责,努力克服困难,出色地完成本职工作的()
在股指期货交易中,期价高估是指期货指数高于对应的理论指数()。
原核生物中具有GTP酶活性的翻译起始因子是()
中国首位80后女航天员王亚平,随神舟十号飞船进入太空飞行15天。飞行中她不会碰到
小斌既想得高分又不愿意努力学习,这种心理冲突属于( )。
当控制对象为“均值和离散程度”时,控制图可选()。 A.p图B.-R图
洋地黄化后,用哪种药物可引起心脏房室传导阻滞()A:氯喹B:青蒿素C:伯氨喹D:乙胺嘧啶E:奎宁
某地区医疗中心重症医学科李主任已有20年的工作经历,抢救过很多危重病人。由于长期的能量透支和巨大的工作压力,李主任最近出现了严重的身心不适,常说“我感觉自...