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
32
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!
According to Paragraph 4, what does Rome plan to do?
选项
A、To make the backpack more comfortable for the wearer.
B、To put the backpack on the market.
C、To test the advantage of the backpack.
D、To promote the backpack in a newspaper or on television.
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/h8Gd777K
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
Migrant(移民的)WorkersInthepasttwentyyears,therehasbeenanincreasingtendencyforworkerstomovefromonecountrytoa
Migrant(移民的)WorkersInthepasttwentyyears,therehasbeenanincreasingtendencyforworkerstomovefromonecountrytoa
EyeMovementandSeveralFaultsinReadingSupposeyoudothisexperimentwithafriend.Getholdofabookwithalargepag
HumanandtheEnvironmentOneofthemostpressingchallengesthattheUnitedStatesandindeedtheworldwillfaceinthen
We’veseenamarkedshiftinourapproachtothesocialissues.
FloridaHitbyColdAirMassInJanuary,2003,theeasterntwothirdsoftheUnitedStateswasatthemercyofabitterlycold
Ihavebeentryingtoquitsmoking.
AopticalinformationBprocessingspeedsCelectronsDpositivechargesEdatatechnologiesFall-opticalsystemsCurrentcomp
Today,conventionalfinancialcontrolsarestillexercisedinsomeminorareassuchasbillingandvocationaltraining.Atpres
SmokingCanIncreaseDepressiveSymptomsinTeensWhilesometeenagersmaypuffoncigarettesto"self-medicate"againstt
随机试题
当今世界和平与发展的主要障碍是()
血清中抗线粒体抗体阳性多见于
甲粮油贸易公司与乙食用油脂厂签订一份合同,双方约定由甲方提供毛糖油10吨,乙方负责加工成精糖油。乙方应以甲方提供的毛糖油酸价为基数,降低8个酸价,并脱色去杂,使其达到食用标准,加工费由甲方提货时付清。合同签订后,乙方就甲方提供的毛糖油按约定降低8个酸价处理
沪深300成长指数和沪深300价值指数的样本数量均固定为( )只。
有人说喜欢吃甜食会让人发胖,但对某市各地区18至23岁年轻人进行的调查显示,喜欢吃甜食的年轻人比不喜欢吃甜食的年轻人的体重更轻。由此看来,经常吃甜食并不会让人发胖。下列选项如果为真,最能削弱上述论断的是:
依次填入下列各句横线处的词语,恰当的一组是()。①这是我们白家祖辈______下来的秘方,就是掉脑袋,也不能让日本人拿去!②几家上市公司的倒闭,引发了股市的大幅______;证监会对此予以高度关注。
人脑内神经元信号传递的主要方式是
法律的作用是指法律对人的行为和社会关系所产生的影响。社会主义法律除确立和维护社会主义的政治制度、经济制度、社会秩序以及推动社会改革与进步外,还具有指引、预测、评价、强制、教育等重要作用。在法律的所有这些作用之中,最首要的作用是
InWarMadeEasyNormanSolomondemolishesthemythofanindependentAmericanpresszealouslyguardingsacredvaluesoffreeex
Seafoodcouldbegoingoffalotofmenusastheworldwarms.Morethanhalfofagroupoffish【C1】______forthemarinefoodwe
最新回复
(
0
)