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
What’ s the main topic of this passage?
What’ s the main topic of this passage?
admin
2019-01-11
45
问题
What’ s the main topic of this passage?
Before a new plane goes into service, every part of it is tested again and again. But there are two tests that are more important than all the others. In , the first test, a modern airliner must fly at very high altitudes. Air must be pushed into the airliner so that the passengers can breathe. The metal structure of the plane has to be very strong for this reason. When the airliner is filled with air, the air presses against the skin of the plane inside. The pressure on a small window, for instance, is like a huge, giant foot that is trying to get out. If a small part of the plane were to crack, the plane would explode in the sky. It is lowered into a huge tank of water to test the structrue of the plane. Then it is filled with air. The pressure inside the plane is greater than it ever will be when it is in the air. Finally, there is an explosion. Engineers can discover which part of the plane has cracked.
In the second test, the test pilot must find out exactly what happens when all the engines are shut off at once. He takes the plane up very high. Then he shuts the engines off, the plane begins to fall like a stone. It is the pilot’s job to find out how he can control the plane again. These two tests are examples of how planes are made safe before they ever carry passengers.
选项
A、Because without air the plane can’t fly.
B、Because the plane needs air for its fuel.
C、Because the passengers’ lives depend on air.
D、Because the passengers have paid for it.
答案
C
解析
转载请注明原文地址:https://jikaoti.com/ti/1YfsFFFM
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
HowmanychildrendidSusanandMichaelinterview?
HowmanychildrendidSusanandMichaelinterview?
Rain
Forthispart,youareallowedtowriteacompositionabout"TheWayToSuccess".Youressayshouldincludethefollowingpoints
"Migration"inthispassagemeans
"Migration"inthispassagemeans
Standardusageincludesthosewordsandexpressionsunderstood,used,andacceptedbyamajorityofthespeakersofalanguagei
Standardusageincludesthosewordsandexpressionsunderstood,used,andacceptedbyamajorityofthespeakersofalanguagei
showofself-confidence
随机试题
《保护工业产权巴黎公约》于1883年签订,现大多数国家采用的是()
设z=f(xy,y),其中f具有二阶连续偏导数,求
Pelger-Hufit畸型的特点是
可同时扩张动脉和静脉的药物是
高压氧疗治疗一氧化碳中毒的主要机制是
患者,女性,52岁。近期乏力明显,食欲下降,巩膜黄染,医嘱查碱性磷酸酶,护士取血的时间是
项目竣工验收合格后,方可投入使用。对未经验收或验收不合格就交付使用的,要追究()的责任,造成重大损失的,要追究其法律责任。
企业向商业银行购买远期利率合约(FRA)的主要目的是()。
教学是学校教育中最基本的活动,在整个教育体系中居于中心地位。()
A、 B、 C、 D、 A整体上,图形相似,对比阴影小箭头,每行图形相似度更高,考虑每行图形间的位置变化。第一个图形顺时针旋转90°得到第二个图形,第二个图形左右翻转得到第三个图形,此题答案选A。
最新回复
(
0
)