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
专升本
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
2019-01-24
26
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 past 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 device such as portable computers, radio and cassette players and mobile telephones.
RTCA, an organization which advises the aviation(航空)industry, has recommended that all airlines ban(禁止)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 device 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(易受损的)to interference raises the risk that terrorists may use radio systems in order to damage navigation equipment. As worrying, though, is the passenger who can ’ t hear the instructions to turn off his radio because the music’ s too loud.
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 it remains a mystery what wavelengths are liable to be interfered with.
C、Because research scientists have not been able to produce the same effects in labs.
D、Because experts lack adequate equipment to do such research.
答案
C
解析
第三段because后面给出了解释:因为他们不能在实验室重现这些影响,所以他们没办法知道干扰是不是有危险。所以选C。A文中没有说过,B和第二句相反,D没有提到。
转载请注明原文地址:https://kaotiyun.com/show/9AaC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
WhentheOldandNewCitiesofJerusalemwerereunitedin1967,arecentlywidowedArabwoman,whohadbeenlivinginOldJerusa
AmericanBlacksexperiencedarevolutionafter1945,arevolutioninexpectations.FollowingWorldWarII,thesteadymovement
JohnPaulJoneswasoneofthefoundersoftheUnitedStatesNavy.DuringtheRevolution,thecoloniesweredesperate.Theyneed
Unlikemodernanimalscientists,dinosaurscientistscannotsitonahillsideandusetelescopestowatchdinosaursinorderto
Enoughsleepisimportanttohealth.Theamountofsleep【C1】______dependsontheageofthepersonandtheconditionsinwhichs
Peopleareusedtospeakingtheirnativelanguage,soimmigrantsarehavingmanyproblemsbetweenthefirstgenerationandthes
TheNobelPrizesareawardsthataregiveneachyearforspecialthingsthatpeopleorgroupsofpeoplehaveachieved.Theyare
TheNobelPrizesareawardsthataregiveneachyearforspecialthingsthatpeopleorgroupsofpeoplehaveachieved.Theyare
Atfirstglance,therehardlyseemstobeanycomparisonbetweenRavennaandRome,butbackinthe5thcentury,itwasRavennat
ResearchershavefoundthatREM(rapideyemovement)sleepisimportanttohumanbeings.Thistypeofsleepgenerallyoccursfour
随机试题
患儿,11岁。因急性肾炎住院治疗1个月,现水肿消退,血压正常,血沉9mm,尿蛋白(±),尿红细胞2~4个/HP,出院后医嘱哪项是合适的
消费者有权要求经营者提供任何商品的价格、产地、生产者、等级、检验合格证明、使用方法说明书、售后服务等情况。
分析下列各句产生歧义的原因。小店关门了。
继发性青光眼引起眼压升高的原因
采购成本的控制主要包括()。
根据规定。会计人员继续教育的对象为所有持有会计从业资格证书的人员。()
“中华人民共和国公民有依照法律纳税的义务”这一规则是()。
有这样的措施:(1)广州、东莞给低收入人群发红包;(2)西安给购买商品房的群众提供补贴。你怎么看?
市盈率法(华东师范大学2013真题;华中科技大学2016真题)
Whatdoesthemanwantticketsfor?
最新回复
(
0
)