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
Electric Backpack Backpacks are convenient. They can hold your books, your lunch, and a charge of clothes, leaving your han
Electric Backpack Backpacks are convenient. They can hold your books, your lunch, and a charge of clothes, leaving your han
admin
2011-01-01
53
问题
Electric Backpack
Backpacks are convenient. They can hold your books, your lunch, and a charge of clothes, leaving your hands free to do other things. Someday, if you don’t mind carrying a heavy load, your backpacks might also power your MP3 player, keep your cell phone running, and maybe even light your way home.
Lawrence C. Rome and his colleagues from the University of Pennsylvania in Philadelphia and the Marine Biological Laboratory in Woods Hole, Mass. , have invented a backpack that makes electricity from energy produced while its wearer walks. In military actions, search and-rescue operations, and scientific field studies, people rely increasingly on cell phones, global positioning system (GPS) receivers, night-vision goggles, and other battery-powered devices to get around and do their work. The backpack’s electricity-generating feature could dramatically reduce the amount of a wearer’s load now devoted to spare batteries, report Rome and his colleagues in the Sept. 9 Science.
The backpack’s electricity-crew, ring powers depend on springs used to hang a cloth pack from its metal frame. The frame sits against the wearer’s back, and the whole pack moves up and down as the person walks. A gear mechanism converts vertical movements of the pack to rotary motions of an electrical generator, producing up to 7.4 watts.
Unexpectedly, tests showed that wearers of the new backpack alter their gaits in response to the pack’s oscillations, so that they carry loads more comfortably and with less effort than they do ordinary backpacks. Because of that surprising advantage, Rome plans to commercialize both electric and non-electric versions of the backpack.
The backpack could be especially useful for soldiers, scientists, mountaineers, and emergency workers who typically carry heavy backpacks. For the rest of us, power-generating backpacks could make it possible to walk, play video games, watch TV, and listen to music, all at the same time. Electricity-generating packs aren’t on the market yet, but if you do get one eventually, just make sure to look both ways be{ore crossing the street!
What is the most important feature of the backpack invented by Lawrence C. Rome and his colleagues?
选项
A、It produces electricity for electronic devisees while the wearer walks.
B、It can be used as cell phones, GPS in the military actions or field studies.
C、It is small and convenient.
D、It is light and easy to carry.
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/L8Gd777K
本试题收录于:
职称英语综合类基础题库职称英语分类
0
职称英语综合类基础
职称英语
相关试题推荐
Pesticides(杀虫剂)Whydopesticides(杀虫剂)fitintothepictureofenvironmentaldisease?Wehaveseenthattheynowpollutesoi
EyeMovementandSeveralFaultsinReadingSupposeyoudothisexperimentwithafriend.Getholdofabookwithalargepag
HumanandtheEnvironmentOneofthemostpressingchallengesthattheUnitedStatesandindeedtheworldwillfaceinthen
HumanandtheEnvironmentOneofthemostpressingchallengesthattheUnitedStatesandindeedtheworldwillfaceinthen
Successfulleadersdominateeventsratherthanreacttothem.
Whichofthefollowingstatementsisnotmeantinthefirsttwoparagraphs?Accordingtothesecondparagraph,inwhichareasd
Today,conventionalfinancialcontrolsarestillexercisedinsomeminorareassuchasbillingandvocationaltraining.Onethi
SmokingCanIncreaseDepressiveSymptomsinTeensWhilesometeenagersmaypuffoncigarettesto"self-medicate"againstt
TheSmog(烟雾)Foroveramonth,Indonesiawasincrisis.Forestfiresragedoutofcontrolasthecountrysuffereditsworst
Ourstatisticsshowthatweconsumeallthatwearecapableofproducing.
随机试题
由后天学习而决定的,与社会文化有密切联系的能力是()
脑出血患者急性期绝对卧床休息的时间为
人工流产术后10天仍有较多的阴道出血,首先考虑的诊断是
以下属于激励理论的是()。
乙是A市的建材经销商,因资金周转困难,便从A市甲处借了50万元人民币,购买了一批建材,并销售给了B市的丙,约定货款为60万元人民币,但丙未付款。乙与丙约定的合同履行地在A市。后来,甲要求乙还钱,乙说因为丙没有支付贷款,所以无力偿还。鉴于此,甲欲直接起诉丙,
(05年)
作函数y=的图形.
计算机软件分系统软件和应用软件两大类。其中处于系统软件核心地位的是()。
如果在SQL查询的SELECT短语中使用TOP,则应该配合使用
Theysaythatsticksandstonesmaybreakyourbones,butwordswillneverhurtyou.Yetchildhoodbullyingreallycandamageyo
最新回复
(
0
)