Electrical devices(仪器)could soon use power made by human energy. Scientists say they have

Electrical devices(仪器)could soon use power made by human energy. Scientists say they have developed an experimental device that produces electricity from the physical movement of a person walking , British scientist Max Donelan and other scientists in Canada and the United States developed the device.
The device connects to a person’s knee. As the person walks ,the device captures energy each time the person slows down. To do this ,the device helps with the slowing sown movement of the leg, the movements of the walking person push parts of a small machine that produces electricity. Using the device, an adult walking quickly could produce thirteen watts of electricity in just a minute. Donelan says walking at that speed could produce enough power to operate a laptop computer for six minutes.
There are several possible uses for the device. Developers say it could help people who work in areas without electricity to operate small computers. The device could also he used in hospitals to operate heart pacemakers(起博器), it could even be used to assist in the movement of robotic arms and legs.
The experimental version of the device weighs about one and a half kilograms, but it is too costly for most people to buy, but the researchers hope to make a lighter, less costly version, An improved version should be ready in one year.
The developers hope the device will one day help developing countries; nearly twenty five percent of people around the world live without electric power.
A similar product was invented in 2005 by Larry Rome of the University of Pennsylvania, He created a bag carried on a person’s back that also produces power from walking. The knee device does not produce as much electricity as the bag, but the bag requires the walker to carry a load of twenty to thirty kilograms.
【小题1】. The second paragraph mainly talks about A．who developed the deviceB．how the device worksC．several possible uses for the devicesD．how much electricity the device can produce【小题2】. What is the disadvantage of the experimental version of the device?A．It is too heavy for the walker to bearB．It is too complex for people to useC．It is too expensive for most people to affordD．It will slow down one’s walking speed【小题3】. Compared with the device designed by Larry Rome, this new device A．produces power without adding more loads to the walkerB．can produce more power in a much shorter timeC．needs to be equipped with a batteryD．can help the walker walk faster【小题4】. From the passage, we can learn that the electrical device can A．help housewives operate the washing machineB．make it much easier for us to go onlineC．produce more electricity than that invented by Larry RomeD．be applied in medical fields to operate heart pacemakers【小题5】. What would be the best title for the passage
A. First device powered by walking will soon be on the market
B. Advanced technology brings in a new way to operate heart pacemakers
C. Device gives new meaning to the idea of power walking
D Human energy will become a main source of electricityB

(答案→)B 解析：本文讲述科学家研制出一种固定在人膝盖上的发电装置。这种装置可通过收集人走路时损失的能量发电。【小题1】推理题，第二段主要讲了这种电子装置的工作原理，即它是如何利用人步行来发电的。故选B。【小题2】细节题，根据第四段中“it is too costly for most people to buy”可知这种实验版的设备费用太高，大多数人买不起。故选C。【小题3】推断题。根据末段可知，过去Larry Rome发明的设备虽然也是靠行走获取能量，但是需要步行者背重达20到30公斤的负荷，而这种佩戴在膝盖上的设备重量只有1.5公斤，不需增加步行者的太多负担。故选A。【小题4】细节题，根据文章第三段“the device could also be used in hospitals to operate heart pacemakers”可直接选出答案D项。A项文中没有涉及到，B项表述不科学，根据文章最后一段可以推断C项表述错误。故选D。【小题5】主旨题，文章主要突出的内容是这种新的电子设备使得利用人步行获取能量变得轻松、容易。故选C。

就是这个解释