The (周期) of the seasons makes a year. 题目和参考答案——青夏教育精英家教网—

题目内容

The________ (周期) of the seasons makes a year.

答案：cycle
提示：

练习册系列答案

课课通课程标准思维方法与能力训练系列答案

钟书金牌教材金练系列答案

名牌学校分层课课练系列答案

培优夺冠王系列答案

阅读理解

　　The idea of fighting a noise by making more noise sounds strange, but What's exactly that motor engineers are doing in Germany and some other countries．

　　Carmakers' research and development laboratories have already proved that mixing in more noise with the help of loudspeakers can reduce the unwanted noise．

　　Physicists have known about the technique for a long time．Sound is make up of pressure waves in the air．If two sound waves of the same frequency(频率)mix so that the highest point of one wave happens at the same time with the lowest point of the other wave, the result is no sound．Therefore, by producing a perfect copy of the noise and delaying it by half a wave cycle(周期), we can kill the unwanted noise．Using this technique many carmakers are racing to develop noise-killing systems both inside and outside the cars．Another good thing about the use of noise-killing systems is that it saves the need for a silencer, which not only reduces the weight of a car, but also makes the motor bum less oil and work better．

　　Some engineers believe that the noise-killing system will be used in most cars in 1996．But the carmakers haven't decided if they will put it into production because it would add several hundred dollars to the cost of their ears．

(1)

Which of the following gives a general idea of how the noise-killing system works?
[　　]
A．	By producing pressure waves going in the opposite direction．
B．	By mixing high frequency sound waves with low frequency sound waves．
C．	By making copies of the unwanted sound waves and letting them out a little later．
D．	By mixing new sound waves with the noise and sending them out together．

(2)

Besides its main function the noise-killing system can ________．
[　　]
A．	make a car lighter
B．	make a car quieter
C．	reduce the cost of a silencer
D．	improve the performance of a silencer

(3)

The noise-killing system is not yet popular mainly because ________．
[　　]
A．	it increases the cost of car production
B．	carmakers are not sure if it is necessary
C．	it is still being tried out
D．	people still have their doubts

Do you find getting up in the morning so difficult that it's painful? This might be called laziness, but Dr Kleitman has a new explanation. He has proved that everyone has a daily energy cycle(循环;周期).

During the hours when you labor at work, you may say that you're "hot". That's true. The time of day when you feel most energetic is when your cycle of body temperature is at its peak. For some people, the peak comes during the morning. For others it comes in the afternoon or evening. No one has discovered why this is so, but it leads to such familiar monologues as: "Get up, John! You'll be late for work again!" The possible explanation for the trouble is that John is at his temperature-and-energy peak in the evening. Much family quarreling ends when husbands and wives realize what these energy cycles mean, and which cycle each member of the family has.

You can't change your energy cycle, but you can learn to make your life fit it better. Habit can help, Dr Kleitman believes. Maybe you're sleepy in the evening but feel you must stay up late anyway. Counteract(对抗) your cycle by habitually staying up later than you want to. If your energy is low in the morning but you have an important job to do early in the day, rise before your usual hour. This won't change your cycle, but you'll get up earlier and work better at your low point.

Get off to a slow start, this saves your energy. Get up with a comfortable yawn(哈欠)and stretch. Sit on the edge of the bed a minute before putting your feet on the floor. Avoid the troublesome search for clean clothes by laying them out the night before. Whenever possible, do work in the afternoon and save tasks requiring more energy or concentration for your sharper hours.

4. Which of the following may lead to family quarrels according to the passage?

A. Not knowing the energy cycles.

B. Familiar monologues.

C. Family members have the same energy cycles.

D. One of the family members can control the energy cycle of other family members.

5.You are advised to rise with a yawn and stretch because it will________.

A. help to keep your energy for the day's work

B. help you to keep calm early in the day

C. enable you to work well

D. keep your energy cycle under control all day

A cyclic(周期的) drop in the sun’s radiation can cause unusually cold winters in parts of North America and Europe, scientists say, a finding that could improve long-range forecasts and help countries prepare for snowstorms.

Scientists have known for a long time that the sun has an 11-year cycle during which radiation measured by sunspots on the surface reaches a peak then falls. But explaining a clear link to weather has proved harder.

“Our research confirms the observed link between solar change and regional winter climate,” lead author Sarah Ineson of the UK Met Office told the reporters in an email. The study was published in the journal Nature Geoscience on Monday.

Her team focused on data from the recent solar minimum during 2008-2010, a period of unusual calm for the sun and extreme winters in the United States and parts of Europe that shut down air travel and disrupted(使混乱) business.

The researchers found that a reduction in ultraviolet(UV, 紫外线) radiation from the sun can affect high-altitude wind patterns in the Northern Hemisphere(半球),causing cold winters.

“While UV levels won’t tell us what the day-to-day weather will do, they provide the exciting prospect of improved forecasts for winter conditions for months and even years ahead. These forecasts play an important role in long-term possibility planning,” Ineson, a climate scientist, said.

Ineson and colleagues from Imperial College London and the University of Oxford used satellite data that more accurately measures UV radiation from the sun and found a much greater change than previously thought.

They found that in years of low activity, unusually cold air forms high in the atmosphere over the tropics（回归线）. This causes a redistribution(重新分配) of heat in the atmosphere, making easterly winds that bring freezing weather and snow storms to northern Europe and the United States and milder weather to Canada and the Mediterranean.

When solar UV radiation is stronger, the opposite occurs.

Ineson’s team used the data in a complex computer model that simulates (模拟) long-term weather patterns. The model successfully reproduced what scientists have observed happening in the upper atmosphere during changes in solar radiation.

More study was needed, though. A key uncertainly in the experiment lay in the satellite data used, because it covers only a few years. “So questions remain concerning both accuracy and also applicability to other solar cycles,” she said.

50. The new finding claims cold winters in the North Hemisphere can be caused by________.

A. a sharp rise in the amount of sunspot

B. a complex computer model simulation

C. a clear link between the sun and the earth

D. a decrease in the sun’s UV radiation

51. It has long been known by scientists that ________.

A. UV radiation can affect high-altitude wind patterns.

B. there’s a clear link between the sun’s activity and weather.

C. they can predict day-to-day weather conditions from UV levels

D. the sun’s radiation reaches a peak every eleven years

52. According to the passage, the following statements are correct EXCEPT______.

A. the research team used a complex computer system to monitor the atmosphere

B. the new finding could improve long-term weather prediction

C. the years 2008-2010 were a period when the sun’s radiation fell

D. extreme winters affected air travel and business in parts of Europe

53. What will happen if the sun turns into years of high activity according to the finding?

A. Canada and the Mediterranean will have milder weather.

B. Burning hot weather will appear in northern Europe and the United States.

C. Freezing cold weather will appear in northern Europe and the United States.

D. The whole Northern Hemisphere will suffer from extreme winter day.

54. It can be inferred from the passage that ________.

A. the research doesn’t seem accurate enough due to limited satellite data used

B. long-term weather conditions can be accurately predicted depending on UV levels

C. climate scientists have just begun their research in severe weather forecast

D. research have analyzed the data collected in eleven years

试题分类