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—

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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/nanoelectromechanreal 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.
【小题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.

【小题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.

【小题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.

【小题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.

【小题5】The text is most probably a ________.

A．science news report	B．book review
C．newspaper ad	D．science fiction story

【小题1】C【小题1】B【小题1】D【小题1】C【小题1】A

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56. You may find the above advertisement __________.

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China_is_going_green. In order to reduce air pollution and oilshortages, automobile manufacturers have announced their plans to develop hybrid vehicles (混合燃料汽车) for the Chinese market. Toyota's hybrid car Prius will be ready to drive in China this week. Let's have a look at the new car.
Any vehicle is a hybrid when it combines two or more sources of power. Hybrid cars run off a rechargeable battery and gasoline. Hybrid cars have special engines, which are smaller than traditional gasoline engines. They run at 99 percent of their power when the car is cruising (匀速行驶). A specially designed battery motor provides extra power for running up hills or when extra acceleration is needed.
Step into a Prius, and turn on the engine. The first thing you notice is how much quieter it is than a traditional car. At this point, the car's gasoline engine is dormant (休眠). The electric motor will provide power until the car reaches about 24 km/h. If you stay at a low speed, you are effectively driving an electric car, with no gasoline being used, and no waste gas gives off.
The onboard(车载的) computer makes the decision about when to use a gas engine, when to go electric, and when to use a combination of the two. If you go over 24 km/h, when you step on the gas pedal (油门), you are actually telling the computer how fast you want to go.
The electronic motor recharges automatically using a set of batteries. When driving at high speed, the gasoline engine not only powers the car, but also charges the batteries. Any time you use the brake, the electric motor in the wheels will work like a generator and produce electricity to recharge the batteries. As a consequence, the car's batteries will last for around 200,000 miles.
【小题1】The author writes this passage mainly to________.

A．teach people how to drive a hybrid car

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

【小题2】The first sentence probably refers to ________.

A．there will be more and more green land in China

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

【小题3】Which of the followings is NOT true?

A．The hybrid cars reduce air pollution and oilshortages.

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.

From school to band practice, the Venturi Eclectic is an Earth-friendly way to get where you want to go. This battery-powered, zero-emission (meaning it doesn't pollute the air) vehicle runs mainly on renewable energy. Solar panels on the Eclectic's roof absorb sun rays when you're driving. On windy days, you can connect a machine to the car's roof that collects energy from the wind while you're parked. The Eclectic's top speed is 28 miles an hour; the battery lasts for 31 miles before it needs to be recharged. Zipping (迅速行进) around the neighborhood has never been better.

Here's an eco-friendly way to tell time: Simply fill the Bedol Water-powered Clock's tank (箱) with water, add some lemon juice, and the clock will display the time without the need for environmentally harmful batteries. There are two sets of metal electrodes(电极) inside the water tank. Water contains ions (离子) that carry negative and positive charges. These ions complete a charge between the electrodes, creating enough energy to power the clock. Just refill the tank every few weeks, and this clock will keep on ticking.

You’re having a blast at your friend’s birthday party. But when it's time to bring out the cake, everyone crowds around, blocking your view. No worries. Throw the Triops into the air, and this clever camera catches the view from above. The Triops can take three pictures at once, each from different angles. You can also record sounds and command the Triops to start shooting (拍摄)whenever it hears that noise. That's one smart camera.
【小题1】According to the passage, the Venturi Eclectic .