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
Please Fasten Your Seatbelts Severe turbulence(湍流)can kill aircraft passengers. Now, in test flights over the Rocky Mountain
Please Fasten Your Seatbelts Severe turbulence(湍流)can kill aircraft passengers. Now, in test flights over the Rocky Mountain
admin
2015-07-04
96
问题
Please Fasten Your Seatbelts
Severe turbulence(湍流)can kill aircraft passengers. Now, in test flights over the Rocky Mountains, NASA(美国航空航天局)engineers have successfully detected clear-air turbulence up to 10 seconds before an aircraft hits it.
Clear-air turbulence often catches pilots by surprise. Invisible to radar, it is difficult to forecast and can hurl(用力抛出去)passengers about the cabin. In December 1997, one passenger died and a hundred others were injured when unexpected rough air caused a United Airlines flight over the Pacific to drop 300 meters in a few seconds.
However, passengers can avoid serious injury by fastening their seatbelts. "It is the only antidote(对策)for this sort of thing, " says Rod Bogue, project manager at NASA’s Dryden Flight Research Center in Edwards, California.
The centre’s new turbulence detector is based on lidar, or laser radar. Laser pulses are sent ahead of the plane and these are then reflected back by particles in the air. The technique depends on the Doppler effect. The wavelength of the light shifts according to the speed at which the particles are approaching. In calm air, the speed equals the plane’s airspeed. But as the particles swirl(打漩)in rough air, their speed of approach increases or decreases rapidly. The rate of change in speed corresponds to the severity(激烈程度)of the turbulence.
In a series of tests that began last month, a research jet flew repeatedly into disturbed air over the mountain ridges(山脉)near Pueblo, Colorado. The lidar detector spotted turbulence between 3 and 8 kilometers ahead, and its forecasts of strength and duration corresponded closely with the turbulence that the plane encountered.
Bogue says that he had "a comfortable amount of time" to fasten his seatbelt. The researchers are planning to improve the lidar’s range with a more powerful beam. The system could be installed on commercial aircraft in the next few years.
We can infer from the fifth paragraph that______.
选项
A、the lidar detector can successfully forecast turbulence
B、researchers are not sure about the effectiveness of the lidar detector
C、passenger planes will be used in further experiments
D、no more test flights are needed
答案
A
解析
此题要求根据第五段的信息判断下面哪句话是正确的。显然,选项A符合原文的意思,为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/3sLd777K
本试题收录于:
职称英语理工类B级题库职称英语分类
0
职称英语理工类B级
职称英语
相关试题推荐
AthatmaycauseourbloodvesselstobecomemoreandmorenarrowBforpregnantwomentotakeduringtheirlastsixmonthsofp
FactsaboutStroke1Every45seconds,someoneinAmericahasastroke.Every3.1minutes,someonediesofone.Strokekilleda
ScientistsDevelopWaysofDetectingHeartAttackGermanresearchershave(1)anewgenerationofdefibrillatorsandearlywarn
WhichofthefollowingisNOTtrueofchronicdiseasesintheUS?Thepurposeofthe$15millionprogramisto
AKeepingGoodRelationswithLocalBusinessmenBServiceProvidedbyLocalNewspapersCLargeCirculationoftheNationalNe
AKeepingGoodRelationswithLocalBusinessmenBServiceProvidedbyLocalNewspapersCLargeCirculationoftheNationalNe
The"YouthEmancipation"programmeaimsathelpingyoungpeople______.WhichofthefollowingstatementsisNOTtrueofDionisi
Thenumberofprematurelystoppedclinicaltrialshasincreasedrecently.Someofthetrialswereprobablystoppedearlyforco
Themostcrucialproblemanyeconomicsystemfacesishowtouseitsscarceresources.
ThanksgivingDayTheAmericanThanksgivingDaycelebrationgoesbackto1621.Inthatyear,aspecialdinnerwaspreparedin
随机试题
我国商业银行在法兰克福金融市场发行的以美元为面值的金融债券称为()
简述公务员公开遴选程序。
午餐肉罐头的微生物培养检验应选用以下哪种培养分析方法最为适合()。
膀胱残余尿测定时,以下哪种说法不正确
某女,带下量多,色白或淡黄,质粘稠,无臭气,面色萎黄,神疲纳呆,便溏足肿,舌淡苔白,脉缓弱。治疗首选方为( )。
郭某用暴力殴打杨某,将其强奸。之后对杨某的全身以及物品进行搜索,发现有金项链一条、装有4000元钱的钱包一个、手机一部。郭某将这些东西全部据为己有,下列对郭某的行为,说法不正确的是哪些?
境内单位或者个人违反规定从事境外期货交易的,其依法承担的法律责任是()。
患者,女性,30岁。被汽车撞伤左季肋部1小时来诊。查体:体温37.5℃,脉搏110次/分,血压90/50mmHg。腹平坦,左上腹肌略紧张,局部压痛,腹有跳痛,有移动性浊音(+),听诊未闻肠鸣音。首先应进行的检查是()。
我国《环境保护法》规定,重点排污单位不公开或者不如实公开环境信息的,由县级以上地方人民政府环境保护主管部门()。
关于宪法关系及其特点的说法正确的是().
最新回复
(
0
)