单选题 1.00分

Electrick Backpack 【电子背包】   Backpacks are convenient. They can hold your books,your lunch,and a chan...

Electrick Backpack 【电子背包】
  Backpacks are convenient. They can hold your books,your lunch,and a change 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 MP31player,keep your cell phone running,and maybe even light your way home.
  Lawrence C. Rome and his colleagues from the University of Pennsylvania in Philadelphia2 and the Marine Biological Laboratory in WoodsHole3,Mass.4,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 cellphones,global positioning system (GPS) 5 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 awearer’s load now devoted to spare batteries,report Rome and his colleagues in the Sept.9 Science6.The backpack’s electricity-creating 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 before crossing the street!
文章(16~20)

Backpacks are convenient because
  • A. they can be very large.
  • B. they can hold as many things as you want to carry.
  • C. your hand sare freed to do other things.
  • D. you do not have to carry things with you.

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1 单选题 1.00分
Time to Stop Traveling by Air
  Twenty-five years ago a young British man called Mark Ellingham decided that he wanted a change of scenery. So he went to Australia, stopping off in many countries between. He also decided to write about the experience and produced a guide for other travelers making similar journeys.
  In 1970, British airports were used by 32million people. In 2004, the figure was 216 million. In 2030, according to government forecasts, it will be around 500 million. It's a growth driven by the emergence of low cost airlines, offering access to all parts of the world for less than £100.
  This has made a huge contribution to global warming. One return flight from Britain to the US produces the same carbon dioxide(二氧化碳)as a year's motoring(驾车). A return flight to Australia equals the emissions(排放)of three average cars for a year. And the pollution is released at a height where its effect on climate change is more than double that on the ground.
  Mark Ellingham built his business on helping people travel. Now he wants to help people stop – at least by air.
  He is calling for a £100 green tax on all flights to Europe and Africa, and £250 on flights to the rest of the world. He also wants investment to create a low-carbon economy, as well as a halt to airport expansion.
  Mark Ellingham's commitment is important because his readers aren't just the sort of young and adventurous people who would happily jump on a plane to spend a weekend exploring a foreign culture. They are also the sort of people who say they care about the environment. It's a debate that splits people down the middle.
  The tourist industry has responded by offering offsetting(补偿)schemes. A small increase in the price of a ticket is used to plant trees.
  But critics say that it is not enough to just be carbon neutral. We should be actively cutting back on putting green house gases into the atmosphere. And for the average person, making a plane journey will be his or her largest contribution to global warming. It maybe good to repair the damage we do. But surely it is better not to do the damage in the first place.
文章(1~7)

Mark Ellingham spent quite a few days in China on his way to Australia 25 years ago.
  • A.Right
  • B.Wrong
  • C.Not mentioned