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
Scientists now tend to agree that the noise level for potential hearing loss begins at about 70 decibels. Some of them are very
Scientists now tend to agree that the noise level for potential hearing loss begins at about 70 decibels. Some of them are very
admin
2015-04-24
67
问题
Scientists now tend to agree that the noise level for potential hearing loss begins at about 70 decibels. Some of them are very concerned because normal daily life often exposes people to noise levels of about 70 decibels even inside their homes. Cities have always been noisy, but noise is now spreading to areas that were quiet just a few years ago.
Clearly, something must be done or noise will seriously and permanently maim the population. Fortunately, the knowledge and methods to control noise already exist. As a matter of fact, this is one instance where the knowledge of control methods exceeds the knowledge about the effects on human life and on the environment.
There are two common means for control. The first is reducing noise at its source, and the second is changing the sound path by distance or by shielding.
The second approach is being used more often today as people become more aware of the danger of noise. New building codes require better sound insulation in homes and apartments. More and more towns are passing zoning ordinances that try to segregate noisy factories or airports from residential areas. Sound-absorbent materials and construction designed to block sound paths are slowly coming into use in offices and homes. New highways are being built to redirect traffic noise up and away from nearby areas. Aircraft are increasingly being required to use reduced-power flights around airports.
There are many examples of available noise control methods that are not being used. More flexible building codes would permits the use of quieter kinds of plumbing pipes. Sound-absorbent materials can reduce the noise of motors and engines. Power generators can be quieted with baffles, exhaust silencers, and sound absorbers. Truck tires can be made with quieter treads. In many cases, the most of building quieter machines is the same or only slightly higher than that of the current noisy ones. Even though the new jumbo jets, for example, are quieter than the older ones, yet they are more powerful and carry twice as many passengers.
All of these methods are only partial measures as noisy levels continue to rise. Most specialists in the field agree that much of the solution must come from eliminating some of the noise at its source, therefore saving through prevention the large costs of hearing loss.
Jet pilots are being advised to land______.
选项
A、on longer runways
B、from nearby areas
C、after dark
D、with reduced power
答案
D
解析
细节推理题。根据原文第三段的尾句中的reducing noise at its source与选项D对应,人们要求飞机在机场周围飞行时降低功率。因此可以推断出,飞机在起飞和降落时都要降低功率。故答案为D。
转载请注明原文地址:https://www.kaotiyun.com/show/QyLO777K
0
考博英语
相关试题推荐
Recentlyscientistshavebeen【1】andperfectingothersourcesofenergy:nuclearoratomicpower,solar(sun)power,andsynthetic(
Recentlyscientistshavebeen【1】andperfectingothersourcesofenergy:nuclearoratomicpower,solar(sun)power,andsynthetic(
IhaveneverseenMrs.Clarkbefore,butIknowfromhermedicalchartandthereportIreceivedfromtheprecedingshiftthatt
InMicrosoft’slatestattempttoreachouttobloggers,thecompanyrecentlygaveawayexpensivelaptopsloaded【C1】_____itsnew
PsychologistGeorgeSpilichandcolleaguesatWashingtonCollegeinChestertown,Maryland,decidedtofindoutwhether,asmany
Herspirits______atthethoughtofalltheworkshehadtodothatmorning.
ThepsychologyofwarrantiesProtectionracket保单心理学保护之诈Ifextendedguaranteesareoverpriced,
ThetwoclawsofthematureAmericanlobsteraredecidedlydifferentfromeachother.Thecrusherclawisshortandstout;thec
Inolddays,whenaglimpseofstockingwaslookeduponassomethingfartooshockingtodistracttheseriousworkofanoffice,
Futuristshaveidentifiedtwochangesthatseemtobecentraltocontemporarysociallife.First,theU-nitedStatesisbeingre
随机试题
理想是()
苦泄的含义包括
改性沥青混合料宜采用间歇式设备生产,该设备具有()特点。
小唐十七岁,以个人积蓄1000元在慈善拍卖会拍得某明星表演用过的道具,市价约100元。事后,小唐觉得道具价值与其价格很不相称,颇为后悔。关于这一买卖合同,下列说法正确的是()。
使用等额本息还款法的贷款,每月还款额中()。
根据个人所得税法律制度的规定,下列各项中,属于工资、薪金所得项目的是()。(2008年)
张先生:应该向吸烟者征税,用以缓解医疗保健事业的投入不足。因为正是吸烟导致了许多严重的疾病。要吸烟者承担一部分费用,来对付因他们的不良习惯而造成的健康问题,是完全合理的。李女士:照您这么说,如果您经常吃奶油蛋糕或者肥猪肉,也应该纳税。因为如同吸烟一样,经
例如:女:晚饭做好了,准备吃饭了。男:等一会儿,比赛还有三分钟就结束了。女:快点儿吧,一起吃,菜凉了就不好吃了。男:你先吃,我马上就看完了。问:男的在做什么?A洗澡B吃饭C看电视√
Onedayawomanwentintothelaundry(洗衣店)【16】.She【17】toseetheowner."【18】WhatcanI【19】you,madam?"saidamankindly.He
Readthisfollowingnewsaboutemploymentopportunitiesforgraduates.ChoosethebestwordtofilleachgapfromA,B,C,orD
最新回复
(
0
)