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
You never see them, but they’re with you every time you fly. They record where you are going, how fast you’re traveling and whet
You never see them, but they’re with you every time you fly. They record where you are going, how fast you’re traveling and whet
admin
2015-02-09
39
问题
You never see them, but they’re with you every time you fly. They record where you are going, how fast you’re traveling and whether everything on your airplane is functioning normally. Their ability to withstand almost any disaster makes them seem like something out of a comic book. They’re known as the black box.
When planes fall from the sky, as a Yemeni airliner did on its way to Comoros Islands in the India ocean June 30, 2009, the black box is the best bet for identifying what went wrong. So when a French submarine(潜水艇)detected the device’s homing signal five days later, the discovery marked a huge step toward determining the cause of a tragedy in which 152 passengers were killed.
In 1958, Australian scientist David Warren developed a flight-memory recorder that would track basic information like altitude and direction. That was the first mode for a black box, which became a requirement on all U.S. commercial flights by 1960. Early models often failed to withstand crashes, however, so in 1965 the device was completely redesigned and moved to the rear of the plane - the area least subject to impact - from its original position in the landing wells(起落架舱). The same year, the Federal Aviation Authority required that the boxes, which were never actually black, be painted orange or yellow to aid visibility.
Modern airplanes have two black boxes: a voice recorder, which tracks pilots’ conversations, and a flight-data recorder, which monitors fuel levels, engine noises and other operating functions that help investigators reconstruct the aircraft’s final moments. Placed in an insulated(隔绝的)case and surrounded by a quarter-inch-thick panels of stainless steel, the boxes can withstand massive force and temperatures up to 2,000℉. When submerged, they’re also able to emit signals from depths of 20,000 ft. Experts believe the boxes from Air France Flight 447, which crashed near Brazil on June 1, 2009, are in water nearly that deep, but statistics say they’re still likely to turn up. In the approximately 20 deep-sea crashes over the past 30 years, only one plane’s black boxes were never recovered.
Why did the Federal Aviation Authority require the black boxes be painted orange or yellow?
选项
A、To distinguish them from the colour of the plane.
B、To caution people to handle them with care.
C、To make them easily identifiable.
D、To conform to international standards.
答案
C
解析
转载请注明原文地址:https://kaotiyun.com/show/gOq7777K
0
大学英语四级
相关试题推荐
A、Internetdidn’thelpincontrollingweight.B、Thosewithoutanyprogramregainedtheiroriginalweight.C、Thosewithpersonal
A、Becauseherteacherfoundthatshehadgreatskill.B、Becauseshedidn’thavetroubleatschoolanymore.C、Becauseshecould
A、Hebuyssomemedicineforher.B、Hetriestofindajobforher.C、Helendshersomemoney.D、Heletsherliveinhisapartmen
Lessthan60%ofstudentsnowenteringfour-yearAmericancollegesarelikelytograduate.The【B1】______rateislowerthanfora
A、Theycarealotaboutchildren.B、Theyneedlookingafterintheiroldage.C、Theywanttoenrichtheirlifeexperience.D、The
A、Acollegedegree.B、Goodcreditrecord.C、Livinginthecollege.D、Anageofatleast18years.D选项中的Goodcreditrecord和Anage
A、Theyhuntforfood.B、Theyhuntformoney.C、Theymistreatanimals.D、Theyhuntoldanimals.A短文中间引用大型动物猎杀者在他们的日记中写的话,理解了其中提到的
A、Printingmoney.B、Determiningstatetaxes.C、Makingtreatieswithforeigncountries.D、Passinglawsaffectingtradebetweenst
随机试题
A.肾小球新月体形成B.部分肾小球节段性硬化C.大部分肾小球纤维化,小部分肾小球代偿肥大D.肾小球毛细血管壁弥漫性增厚弥漫性新月体性肾小球肾炎的病理特点是
某机场的机械师陆某对机场领导人员心怀不满,在某次为等待执行任务的一架波音747客机进行机械检修时,故意对飞机的发动机装置进行了破坏。但恰好这架飞机此次没有投入运营。在第二天运营前机械师陈某在对飞机进行检修时发现了故障并及时进行了排除。对陆某的行为如何认定?
社会工作者张莉对某社区的青少年群体进行了调研和分析,发现有一些青少年整天游手好闲,对生活没有明确的目标,特别是对就业形势缺乏了解,对职业生涯缺少规划。为此,张莉设计了一个“职业生涯规划”小组,招募了11名社区青少年。通过两个多月的小组活动,这批青少年的态度
《中华人民共和国会计法》赋予财政部门对会计行为的监督权,其他拥有法律赋予的对有关会计工作实施监督并对相关会计违法行为进行处罚职权的部门有()。
下面不属于《普通高中语文课程标准(实验)》中“评价的基本原则”的一项()。
【2015重庆云阳选】最早在大学里开设教育学课程的是()。
现代植物保护学科发展的总趋势是朝着微观、宏观两个方向发展,在宏观指导下同时进行微观研究,并将微观资料进行宏观分析和处理,不断发展病虫治理新理论和新技术。在宏观方面,应用生态学和系统工程学的原理和方法建立农业生态系统中病虫害监控决策体系;在微观方面,以分子生
根据下图,回答116-120题。全民所有制单位职工劳保福利费在B年用于医疗费用的支出比用于其他费用的支出多:
已知x满足不等式22x一10.2x+16≤0,则的最大值与最小值之差为
通常数据链路层交换的协议数据单元被称为
最新回复
(
0
)