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
The biggest safety threat facing airlines today may not be a terrorist with a gun, but the man with the portable computer in bus
The biggest safety threat facing airlines today may not be a terrorist with a gun, but the man with the portable computer in bus
admin
2011-03-01
48
问题
The biggest safety threat facing airlines today may not be a terrorist with a gun, but the man with the portable computer in business class. In the last 15 years, pilots have reported well over 100 incidents that could have been caused by electromagnetic interference. The source of this interference remains unconfirmed, but increasingly, experts are pointing the blame at portable electronic devices such as portable computers, radio and cassette players and mobile telephones.
RTCA, an organization which advises the aviation industry, has recommended that all airlines ban such devices from being used during "critical" stages of flight, particularly take-off and landing. Some experts have gone further, calling for a total ban during all flights. Currently, rules on using these devices are left up to individual airlines. And although some airlines prohibit passengers from using such equipment during take-off and landing, most are reluctant to enforce a total ban, given that many passengers want to work during flights.
The difficulty is predicting how electromagnetic fields might affect an aircraft’s computers. Experts know that portable devices emit radiation which affects those wavelengths which aircraft use for navigation and communication. But, because they have not been able to reproduce these effects in a laboratory, they have no way of knowing whether the interference might be dangerous or not.
The fact that aircraft may be vulnerable to interference raises the risk that terrorists may use radio systems in order to damage navigation equipment. As a result, loud music sound makes the passenger unable to hear the instructions turning off his radio, this is the most worrying things to airlines.
Why is it difficult to predict the possible effects of electromagnetic fields on an airplane’s computers?
选项
A、Because it is extremely dangerous to conduct such research on an airplane.
B、Because experts lack adequate equipment to do such research.
C、Because research scientists have not been able to produce the same effects in labs.
D、Because it remains a mystery what wavelengths are liable to be interfered with.
答案
C
解析
第三段第二句给出了答案。
转载请注明原文地址:https://kaotiyun.com/show/3Akd777K
本试题收录于:
公共英语三级笔试题库公共英语(PETS)分类
0
公共英语三级笔试
公共英语(PETS)
相关试题推荐
Ithasalwaysbeenaproblemtodecidewhether"popularmusic"ismusicwhichrepresentsthepeopleorissimplymusicthatthe
Ithasalwaysbeenaproblemtodecidewhether"popularmusic"ismusicwhichrepresentsthepeopleorissimplymusicthatthe
Awebcamisadigitalcamerathatsendsvideoimagestoothercomputerusers.It’saboutthe【C1】______ofagolfballandtyp
Thefollowingchartshowsthepercentageofthestudentsthatwereenrolledincolleges,universitiesandotherinstitutionsof
Bythetimewehadcompletedourpreparations,theskywasbeginningtogrowrapidlylighter,althoughthesunwasnotyetabo
Daltonwonderedwhytheheavierandlightergasesintheatmospheredidnotseparateasoilandwaterdo.Hefinallyconcludedt
Ifyouwanttostayyoung,sitdownandhaveagoodthink.ThisistheresearchfindingofateamofJapanesedoctors,whosayt
SupposethatyouhavereceivedaletterfromyourfriendLiling,whowillattendthefinalexaminationnextweek.Inhisletter
ForanincreasingnumberofstudentsatAmericanuniversities,Oldissuddenlyin.Thereasonisobvious:thegrayingofAmerica
Thelongyearsoffoodshortageinthis’countryhavesuddenlygivenwaytoanapparentabundance.Storesandshopsarechokedw
随机试题
同伴教育最大的特点是同伴之间可以轻松谈论同性恋、性病等
患者痰壅气逆,咳嗽喘逆,痰多胸闷,食少难消,舌苔白腻,脉滑。治疗宜选用()
俄亥俄模式关于领导和行为研究得出的两个主要维度是()。
一男性,39岁,已婚。婚后夫妻感情融洽,生有一女。平时总是穿着女性内衣,夜间穿女性紧身衣,还买了女袜、女高根鞋自用。不管妻子如何反感,仍旧如此。在家为自己制作旗袍,连衣裙,在镜前自我欣赏,十分得意。直到某晚趁妻子女儿外出,匆匆男扮女装,途中被熟人认出,扭送
“自我概念比真实自我对个体的行为及人格有更为重要的作用”,这是()的观点。
从土壤中筛选纤维素分解菌的实验流程是:土壤取样→选择培养→梯度培养→鉴别培养。请据此回答问题:为鉴别纤维素分解菌,将筛选获得的菌液稀释后用_______法接种到刚果红培养基上,然后挑选产生_________的菌落作为菌种进行扩大培养。
事务T1、T2、T3分别对数据D1、D2和D3并发操作,如下所示,其中T1与T2间并发操作(45),T2与T3间并发操作(46)。
要定义一个具有5个元素的一维数组vect,并使其各元素的初值依次是30,50,一88,0和0,则下列定义语句中错误的是()。
•YouwillheartheGeneralManagerofCOSCOintroducingthecompany’sEDIsystem.•Asyoulisten,forquestions1-12,complete
Wherecanpeoplefindthetallestredwoodtrees?
最新回复
(
0
)