Batteries can power anything from small sensors to large systems. While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are much larger 题目和参考答案——青夏教育精英家教网—

题目内容

Batteries can power anything from small sensors to large systems. While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are much larger and heavier than the devices themselves. University of Missouri(MU) researchers are developing a nuclear energy source that is smaller, lighter and more efficient.

“To provide enough power, we need certain methods with high energy density(密度)”，said Jae Kwon, assistant professor of electrical and computer engineering at MU. “The radioisotope(放射性同位素) battery can provide power density that is much higher than chemical batteries.”

Kwon and his research team have been working on building a small nuclear battery, presently the size and thickness of a penny, intended to power various micro / nanoelectromechanical systems (M/NEMS). Although nuclear batteries can cause concerns, Kwon said they are safe.

“People hear the word ‘nuclear’ and think of something very dangerous,” he said, “However, nuclear power sources have already been safely powering a variety of devices, such as pace-makers, space satellites and underwater systems.”

His new idea is not only in the battery’s size, but also in its semiconductor(半导体). Kwon’s battery uses a liquid semiconductor rather than a solid semiconductor.

“The key part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure(晶体结构) of the solid semiconductor,” Kwon said, “By using a liquid semiconductor, we believe we can minimize that problem.”

Together with J. David Robertson, chemistry professor and associate director of the MU Research Reactor, Kwon is working to build and test the battery. In the future, they hope to increase the battery’s power, shrink its size and try with various other materials. Kwon said that battery could be thinner than the thickness of human hair.

1.Which of the following is true of Jae Kwon?

A. He teaches chemistry at MU.

B. He developed a chemical battery.

C. He is working on a nuclear energy source.

D. He made a breakthrough in computer engineering.

2. Jae Kwon gave examples in Paragraph 4_________.

A. to show chemical batteries are widely applied.

B. to introduce nuclear batteries can be safely used.

C. to describe a nuclear-powered system.

D. to introduce various energy sources.

3.Liquid semiconductor is used to _________.

A. get rid of the radioactive waste

B. test the power of nuclear batteries.

C. decrease the size of nuclear batteries

D. reduce the damage to lattice structure.

4. According to Jae Kwon, his nuclear battery _______.

A. uses a solid semiconductor

B. will soon replace the present ones.

C. could be extremely thin

D. has passed the final test.

5.The text is most probably a ________.

A. science news report B. book review

C. newspaper ad D. science fiction story

PART FOUR WRITING (45%)

【答案】

1.C

2.B

3.D

4.C

5.A

【解析】略

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B This wireless transmitter allows you to listen to music from your iPod/MP3 player, on your home or car stereo --- without any wires.

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The unit is wireless so there are no disorganized cables.It is lightweight and easy to carry.

Adds a whole new part to your MP3 experience!

Takes 2 AAA batteries（not supplied）.Click here to buy batteries for this product…

GIFT STATS: iPod/ MP3 Transmitter

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Packaging: Gift pack

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A. in a newspaper B. in a store window

C. in a website D. on a company notice-board

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B．introduce a new kind of “green” car

C．show how to save their gasoline when driving a car

D．announce plans to develop hybrid vehicles for China

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B．China is still young and lacking experience

C．China's new cars are combinations of different green models

D．China has started producing environmentally friendly cars

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B．The car's gasoline engine doesn't work until it reaches about 24 km/h.

C．This kind of car is completely controlled by an onboard computer.

D．A specially designed battery motor provides extra power when needed.

【小题4】What is the most important feature of hybrid cars?

A．They are powered by both a rechargeable battery and gasoline.

B．They are much quieter than traditional cars.

C．They only use 99 percent of their power to run up hills.

D．They have smaller engines than traditional gasoline ones.

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