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．

67．The text is most probably a ________．

A．science news report B．book review

C．newspaper ad D．science fiction

68．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．

69．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．

70．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．

ADCB

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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.

It acts like a miniature radio station, transmitting your music via the FM frequency to the nearest radio.

Simply plug the transmitter into the headphone hole of your MP3 player, select a frequency on the transmitter and then set your radio to that same frequency.

Then sit back and enjoy your digital music in full stereo sound wherever you are.

It Can be used with iPods, MP3 players, portable CD players, cassettes players, games consoles（控制台）or even your laptop computer whenever you want to hear full stereo sound from your radio. Features include:

·LCD display with background lighting （shows time/date/ temperature）

·Full FM frequency range, so you can select the best performing frequency

·Choose from 2 power supplies: 2 AAA batteries or car charger（adaptor provided）

·4 memory channels for storing best performing FM frequencies

·Frequency response: 100Hz – 15000Hz

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

Measures: 7.5 x 4.5cm

Packaging: Gift pack

We can deliver this item to the UK, Europe, and North America.

56. You may find the above advertisement __________.

A. in a newspaper B. in a store window

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

57. What is iPod/MP3 Transmitter?

A. An MP3 player which allows you to enjoy music wherever you are.

B. A kind of equipment that allows you to enjoy music from your iPod/MP3 player.

C. A mini radio station transmitting your music via the FM frequency to the nearest radio.

D. A radio that receives music from your MP3 player.

58. From the advertisement above, we can learn that __________.

A. the product can be used with a lot of electronic equipment

B. the transmitter can only be powered by 2 AAA batteries

C. the unit has organized cables so it is light and easy to carry

D. this item can be delivered to any place around the world

For those who are conditioned to think that learning only happens in a classroom, the world of self-learning can be a little daunting. How do we best take 1 of these new opportunities?

Your interest in the subject is the essential driver of success. You can’t learn what you do not want to learn. Emotion is an important part of the learning 2 . If you are even moderately interested in a subject, give yourself a chance. The key is to get started. If you can create some pleasurable 3 , you may find that the subject grows on you.

Don’t expect to understand things, much less remember them, the first time you study them. Trust that things will get clearer 4 your brain comes to grips with new information. It is like a cross-word puzzle. As you start to put the pieces together, or string the words together, the full picture becomes clearer. The brain learns all the time, but 5 its own schedule. Learning does not take place according to a schedule laid down by a curriculum or teacher. Some things are easier to learn than others. Some things just take 6 to click in. Keep at it, and you will gradually find that things that seem difficult at first , will become easy with time.

Your brain is struggling to form patterns to 7 new input from your learning activities. Sometimes, no matter how long you focus on one subject, your brain is not going to pick it up. If you are stuck, move 8 . Then cover the same general information from a different source, a different book, or a podcast, or an online lecture or a video. Try to become a grazing learner, roaming the countryside, 9 a feedlot learner, just standing there in one spot. The broader your base, the easier it is to learn. Just as the “rich get richer”, the more you know, 10 you can learn.

Take full advantage of the Internet, iTunes, and 11 mobile devices, not to mention good old-fashioned books and magazines. Learn during “dead time”. Listen in your car, on the train, or 12 jogging. Have your learning with you while waiting in the doctor’s office, or listen while checking out at the supermarket. Anytime is 13 time. Remember, you are learning through exposure, not by nailing things down. It is more like moisture accumulation in a 14 , rather than building a brick wall.

The more varied your learning content, and the more varied the ways in which you learn, the 15 the puzzle will become. Different learning activities suit different people, at different times of the day. Vary your activities in order to keep your interest level 16 . Even if listening and reading work best for you, treat yourself to the odd video lecture, or get-together with other learners. This will renew your batteries.

The “loneliness of the distance learner” is a thing of the 17 . Join a learning community on the web, where members share their knowledge and experience. Search for the communities that suit your interests and learning style. You will find encouragement, advice and stimulus from fellow learners, 18 from tutors, teachers and coaches. In these communities, you can measure your progress against your own goals, or compare your experience 19 that of other learners. You can even teach and help others, which is a great way to learn.

Never has it been easier nor more exciting to be a learner. Let constant learning be a major part of your life-style. The 20 will be constant, personally, socially, and professionally.

( ) 1. A. advantage B. place C. possession D. example

( ) 2. A. progress B. process C. pressure D. proposal

( ) 3. A. roads B. streets C. routines D. building

( ) 4. A. with B. if C. unless D. as

( ) 5. A. on B. to C. with D. for

( ) 6. A. shorter B. sooner C. longer D. lower

( ) 7. A. take with B. com with C. go with D. cope with

( ) 8. A. down B. on C. away D. off

( ) 9. A. more than B. less than C. rather than D. other than

( ) 10. A. less B. quicker C. lower D. more

( ) 11. A. same B. similar C. familiar D. various

( ) 12. A. while B. before C. after D. if

( ) 13. A. playing B. learning C. talking D. speaking

( ) 14. A. cloud B. sky C. earth D. sea

( ) 15. A. cleaner B. clearer C. harder D. lower

( ) 16. A. down B. up C. in D. out

( ) 17. A. present B. day C. past D. night

( ) 18. A. as long as B. as far as C. as well as D. as soon as

( ) 19. A. without B. with C. to D. beyond

( ) 20. A. awards B. words C. remarks D. rewards

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.

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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 .