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’re going, how fast you’re traveling and wheth
You never see them, but they’re with you every time you fly. They record where you’re going, how fast you’re traveling and wheth
admin
2013-05-19
40
问题
You never see them, but they’re with you every time you fly. They record where you’re 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 the Comoros Islands in the Indian 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 model 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). That 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 quarter-inch-thick panels of stainless steel, the boxes can withstand massive force and temperatures up to 2,000°F. 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.
What does the author say about Michelle Obama as a First Lady?
选项
A、However many fans she has, she should remain modest.
B、She shouldn’t disappoint the African-American community.
C、However hard she tries, she can’t expect to please everybody.
D、She will give priority to African-American women’s concerns.
答案
C
解析
细节题。根据题目定位到文中第三段最后一句That same year,the Federal Aviation Authority required that the boxes, which were never actually black,be painted orange or yellow to aid visibility. (同年。联邦航空局规定把这个从来都不是真正黑色的盒子涂成黄色以增加能见度.)可知,漆成黄色是为了容易辨认。选项A(与飞机颜色区分),及选项B(提醒人们小心处理),还有选项D(遵守国际规格),均不符合题意。因此选C。
转载请注明原文地址:https://kaotiyun.com/show/PJg7777K
0
大学英语四级
相关试题推荐
Anewgenerationofstorytellershasbeenbornwhosedeceptionshavebenefitedfromacollegeeducation.Apsychologicalres
Anewgenerationofstorytellershasbeenbornwhosedeceptionshavebenefitedfromacollegeeducation.Apsychologicalres
GPSTheGlobalPositioningSystemisaspace-basedtriangulationsystemusingsatellitesandcomputerstomeasurepositions
Wheredopesticidesfitintothepictureofenvironmentaldisease?Wehaveseenthattheynowpollutesoil,water,andfood,tha
Thecommunicationsexplosionisonthescaleoftherail,automobileortelephonerevolution.Verysoonyou’llbeabletorecord
Forsomeeducators,thereisnothingwrongwithfunandgames.AgroupcalledtheEducationArcaderecentlyheldaconferencein
AcademyAwardsEveryFebruaryOscarFeverhitstheentertainmentcommunityandfilmfansaroundtheworld.Hundredsofmilli
AcademyAwardsEveryFebruaryOscarFeverhitstheentertainmentcommunityandfilmfansaroundtheworld.Hundredsofmilli
Forworkersinsmallfirmsemployment______areveryrare,workinghoursarelongerandsafetyrecordspoor.
随机试题
女性,30岁。右前臂骨折石膏绷带固定。协助医师包扎时不正确的护理是()。
其他货币资金主要包括()。
下列属于经济法律关系客体的是( )。
下列关于监事会的说法中,正确的有()。
班主任马老师常对学生说:“先学做人,后学做事,社会需要的是身体健康、和谐发展的建设者和接班人,而不是只会死读书的‘呆子’。”这表明马老师具有()。
近10年来,移居清河界森林周边地区生活的居民越来越多。环保组织的调查统计表明,清河界森林中的百灵鸟的数量近十年来呈明显下降的趋势。但是恐怕不能把这归咎于森林周边地区居民的增多,因为森林的面积并没有因为周边居民人口的增多而减少。以下哪项如果为真,最能削弱题干
设向量组,α1=(a,2,10)T,α2=(一2,1,5)T,α2=(一1,1,4)T,β=(1,b,c)T.试问a,b,c满足什么条件时:(Ⅰ)β可由α1,α2,α3线性表出,且表示唯一?(Ⅱ)β不能由α1,α2,α3线性表出?
设α=(1,一1,a)T是的伴随矩阵A*的特征向量,其中r(AT)=3,则a=___________。
有以下程序:#include<stdio.h>voidfun(inta[],intn){ inti,t; for(i=0;i<n/2;i++){t=a[i];a[i]=a[n-1-i];a[n-1-i
Mary’seyesarered.She______crying.
最新回复
(
0
)