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
考研
Despite increased airport security since September 11th, 2001, the technology to scan both passengers and baggage for weapons an
Despite increased airport security since September 11th, 2001, the technology to scan both passengers and baggage for weapons an
admin
2019-04-19
36
问题
Despite increased airport security since September 11th, 2001, the technology to scan both passengers and baggage for weapons and bombs remains largely unchanged. Travellers walk through metal detectors and carry-on bags pass through x-ray machines that superimpose colour-coded highlights, but do little else. Checked-in luggage is screened by "computed tomography" , which peers inside a suitcase rather like a CAT scan of a brain. These systems can alert an operator to something suspicious, but they cannot tell what it is.
More sophisticated screening technologies are emerging,
albeit
slowly. There are three main approaches: enhanced x-rays to spot hidden objects, sensor technology to sniff dangerous chemicals, and radio frequencies that can identify liquids and solids.
A number of manufacturers are using "reflective" or "backscatter" x-rays that can be calibrated to see objects through clothing. They can spot things that a metal detector may not, such as a ceramic knife or plastic explosives. But some people think they can reveal too much. In America, civil-liberties groups have stalled the introduction of such equipment, arguing that it is too intrusive. To protect travellers’ modesty, filters have been created to blur genital areas.
Machines that can detect minute traces of explosive are also being tested. Passengers walk through a machine that blows a burst of air, intended to dislodge molecules of substances on a person’s body and clothes. The air is sucked into a filter, which instantaneously analyses it to see whether it includes any suspect substances. The process can work for baggage as well. It is a vast improvement on today’s method, whereby carry-on items are occasionally swabbed and screened for traces of explosives. Because this is a manual operation, only a small share of bags are examined this way.
The most radical of the new approaches uses " quadrupole resonance technology". This involves bombarding an object with radio waves. By reading the returning signals, the machines can Identify the molecular structure of the materials it contains. Since every compound—solid, liquid or gas—creates a unique frequency, it can be read like a fingerprint. The system can be used to look for drugs as well as explosives.
For these technologies to make the jump from development labs and small trials to full deployment at airports they must be available at a price that airports are prepared to pay. They must also be easy to use, take up little space and provide quick results, says Chris Yates, a security expert with Jane’s Airport Review. Norman Shanks, an airport security expert, says adding the new technologies costs around $100,000 per machine: he expects the systems to be rolled out commercially over the next 12 months. They might close off one route to destroying an airliner, but a cruel certainty is that terrorists will try to find others.
The delay of employment of x-ray equipment lies in its______.
选项
A、unreliable screening
B、full exposure
C、inadequate efficiency
D、travellers’ modesty
答案
B
解析
这是一道细节分析题,测试考生对原文细节的全面分析能力。本题答案的信息来源在第三段的倒数第二、三句,其大意是:“但是一些人认为X光探测技术显示的内容过多。在美国,民权组织阻碍了X光探测技术仪器的引人和使用,他们认为这种仪器具有过度的侵扰性”。由此可以推断本题的正确选项应该是B。考生在阅读时要注意对原文细节的准确分析和理解。
转载请注明原文地址:https://kaotiyun.com/show/tznZ777K
0
考研英语一
相关试题推荐
InEurope,therehasbeenaseriousdeclineinphysicalactivityoverthepast50years.Adultsaged20-60years【C1】______500kca
InEurope,therehasbeenaseriousdeclineinphysicalactivityoverthepast50years.Adultsaged20-60years【C1】______500kca
Ayoungconsultant’slifeistiring.A【C1】______weekstartsbeforedawnonMonday,witharushtotheairportanda【C2】______to
Prewritingreferstostrategiesyoucanusetogenerateideasbeforestartingthefirstdraftofapaper.Prewritingtechniques
People’sfinancialhistoryhasastrongimpactontheirtasteforrisk.LookingatsurveysofAmericanhousehold【C1】______from1
ThereisgrowinginterestinEastJapanRailwayCo.ltd.,oneofthesixcompanies,createdoutoftheprivatizednationalrailw
ThereisgrowinginterestinEastJapanRailwayCo.ltd.,oneofthesixcompanies,createdoutoftheprivatizednationalrailw
ThereisgrowinginterestinEastJapanRailwayCo.ltd.,oneofthesixcompanies,createdoutoftheprivatizednationalrailw
TheJanuaryfashionshow,calledFutureFashion,exemplifiedhowfargreendesignhascome.OrganizedbytheNewYork-basednonpr
WilltheEuropeanUnionmakeit?Thequestionwouldhavesoundedstrangenotlongago.Noweventheproject’sgreatestcheerlead
随机试题
A.外周淋巴器官B.补体C.骨髓D.淋巴结E.T及B淋巴细胞属固有免疫应答
A.奎尼丁B.利多卡因C.普萘洛尔D.胺碘酮E.地尔硫革轻度阻滞钠通道的抗心律失常药是
呼吸性酸中毒
照片上两个相邻X线吸收不同的组织影像,其影像界限清楚明了的程度称为锐利度,亦即两部分影像密度的转变是逐渐的还是明确的程度;影响锐利度的因素有几何学模糊、移动模糊、增感屏。下列关于摄影中减小运动模糊的叙述,错误的是
实现初级卫生保健的关键是
A.新疆、甘肃B.内蒙古、甘肃、宁夏C.山西、河南、河北D.浙江、安徽、湖北、湖南、江西E.河北、江苏、河南、安徽防己药材的主产地是
根据公司法有关规定,上市公司发生下列哪些情形,国务院证券管理部门有权决定终止其股票上市?
游离氧化钙引起的水泥安定性不良,可用()进行检测。
乙公司为了扩大生产能力,拟购买一台新设备,该投资项目相关资料如下:资料一:新设备的投资额为1800万元,经济寿命期为10年。采用直线法计提折旧,预计期末净残值为300万元。假设设备购入即可投入生产,不需要垫支营运资金,该企业计提折旧的方法、年限、预
已知随机变量X的分布函数F(x)是连续的严格单调函数,Y=1—2X,F(0.25)=0.75,P{Y≤k}=0.25,则k=__________。
最新回复
(
0
)