As children grow up, they become curious about different kinds of things. When they are babies, they are interested in the parts of their bodies and in the smiles of their mothers. The they become interested in the physical world around them: the plants, the

animals, the sky. Later, they become interested in the things that people have made: wheels, bicycles, cars. And when they are adults, their curiosity continues. Sometimes this curiosity leads to a career (生涯、职业) in science.

Scientists spend their lives trying to find out about the world. Those who work with the earth sciences study the earth, the oceans, and the skies. Other scientists who study living things work with the biological sciences. A third group of scientists study the physical sciences, e. g. physics, chemistry .

These scientists have already discovered a lot about our world. For example, they tell us why your heart beats fast when you run. They say that when you are quiet, your heart normally beats sixty-five or seventy-five times a minute. Your heart is a pump (泵) that pumps blood to all parts of the body. The blood carries oxygen and nutrition. When you run, your muscles work very hard and use the nutrition that the blood carries to them. The muscles need oxygen, too . So your brain sends a signal to the heart. The signal means that the muscles need more nutrition and oxygen. Then the heart beats fast and sends blood quickly to the muscles. It may beat 90 to 140 times a minute.

Of course, scientists cannot answer all of our questions. If we ask, “Why does the ocean water taste salty?”

Scientists will say that the salt comes from rocks. When a rock gets very hot or very cold, it cracks. Rain falls into cracks. The rain then carries the salt into the earth and into the rivers. The rivers carry the salt into the ocean. But then we ask , “What happens to the salt in the ocean? The ocean does not get saltier every year.” Scientists are not sure about the answer to this question.

We know a lot about our world, but there are still many answers that we do not have, and we are curious.　

1.According to the passage, which of the following statements is true?

A．People are curious in the same way.

B．People in different countries are interested in different things.

C．Men and women are curious about different things.

D．People of different ages are interested in different things

2.Scientists who work with the biological sciences study____.

A．the earth , the oceans and the sky

B．man-made things

C．plants and animals

D．ocean water

3.When you run, your muscles need ____.

A．more nutrition and oxygen                B．more signals       C．more salt   D．water

 

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两处为多余选项。
  1   First, the radioactive material must travel from its place of production to the power station. Although the power stations themselves are strongly built’, the ．containers used for the transport of the materials are not． 2 Unfortunately, both’ of these may have an effect on the general public, since they are sure to pass near, or even through heavily populated areas．
Second, there is the problem of waste．  3  It is impossible to make these wastes non—radioactive, and so they must be stored in one of the inconvenient ways ．that scientists have invented．For example? they may be buried under the ground, or dropped into deserted mines, or sunk in the sea．However, these methods do not ’solve the problem, since an earthquake could easily break the containers．
Third, there may occur the danger of a leak or an explosion at the power station．As with the other two dangers, this is not very likely to take place． 4  However, it can happen．
Separately, these three types of dangers are not a great cause for worry．  5 

A．It is unusual for radioactive materials to be transported across land．

B．There are three separate sources of danger in supplying energy by nuclear power．

C．All nuclear power stations produce wastes that in most cases will remain radioactive for thousands of years．

D．The general public are strongly against the nuclear program．

E．So it does not provide a serious objection to the nuclear program．
F．Normally, only two methods of transport are in use, namely road or rail．
G．But when they are taken together, the probability of disaster is extremely high．

There is a definite possibility that the climate of the world may be changing. Some scientists imagine that this could even mean the beginning of another ice age. The effects of such a change in climate on the human population of the world would be startling（惊人的）.
Recent research suggests that the general warming trend of the past hundred years or so may be coming to an end. During the past ten years, meteorologists tell us the average temperature of the Earth has dropped about one degree Fahrenheit. This does not seem like much, but it could have effects on wind and rain patterns which influence the overall weather picture. If these patterns change a lot, it could mean that certain regions of the world may continue to have long droughts while others will possibly suffer from widespread flooding.
What regulates（调节）the climate is not exactly known. Meteorologists believe that clouds may be an important factor in regulating the amount of solar heat held by the Earth, which in turn determines the temperature of the planet. Another possibility is that man’s industrial and agricultural methods may be affecting the natural weather patterns. However, the weather is not understood well enough for scientists to say for certain what is happening to the climate and what side effects this will actually have on the world’s population.
【小题1】According to the passage, the climate of the world seems to    .

A．be getting colder	B．be getting warmer
C．remain the same in the past ten years	D．have good effects on the world’s population

【小题2】Which of the following is TRUE according to the passage?

A．Man’s activities have no effect on the climate.

B．Another ice age will come soon.

C．People don’t care about the changing climate.

D．Scientists are not yet sure about the reason for the changing climate.

【小题3】A meteorologist is a person who        .
reads weather forecasts on radio or television 
B. thinks there will be another ice age
C. studies and knows about the weather       
D. believes there will be widespread flooding
【小题4】 Which of the following may be the factor(s) that affect(s) the natural weather patterns?

A．Clouds.	B．The amount of heat the Earth receives.
C．Man’s industrial and agricultural methods.	D．All of the above.

【小题5】The best title for the passage would be         .

A．Droughts and Floods.	B．Meteorologists
C．The Changing Climate	D．Solar Heat

Scientists are not sure how the brain follows the tracks of time．One theory holds that it has a group of cells specialized to record the intervals （间隔）of time, while another theory holds that some neural processes （神经突）act as an inside clock．
Whichever theory it may be, studies find, the cells have a poor grasp of longer interval．Time does seem to slow during an empty afternoon and race when the brain focuses on challenging work．Stimulants （兴奋剂）, including caffeine, tend to make people feel as if．time is passing faster; complex jobs, like doing taxes, can seem to drag on longer than they actually do．And  emotional  events — a breakup, a promotion, a transformative trip abroad —tend to be sensed as more recent than they actually are, by months or even years．In short, some psychologists say, the findings support the philosopher Martin Heidegger' s observation that time "persists merely as a consequence of the events taking place in it．"
Now researchers are finding that the opposite thing may also be true: if very few events come to mind, then the sense of time does not persist; the brain shortens the interval that has passed．
In one classic experiment, a French explorer named Michel Siffre lived in a cave for two months, cut off from the rhythms of night and day and man-made clocks．He appeared then, convinced that he had been isolated for only 25 days．Left to its own devices, the brain tends to shorten time．
In earlier work, researchers found  that a similar case at work in people’s judgment of intervals that last only moments．Relatively infrequent stimuli, like flashes or tones, tend to increase the speed of the brain' s internal pacemaker．
On an obvious level, these kinds of findings offer an explanation for why other people' s children seem to grow up so much faster than one's own．Involved parents are all too well aware of first step in their own children; however, seeing a cousin's child once every few years, without bothering memories, shortens the time．
【小题1】What can we infer from the first paragraph?

A．Scientists have agreed about how the brain records time．

B．Scientists all think that some cells record the intervals of time．

C．Scientists haven't agreed on how the brain records time．

D．Scientists all hold the theory that neural processes are an inside clock．

【小题2】According．to Paragraph 3, if we have few things to do, the brain will____．

A．make the intervals of time long

B．make the intervals of time short

C．keep a state of rest

D．stop working

【小题3】Which of the following is TRUE according to the passage?

A．Michel Siffre didn' t think he had stayed in the cave for as long as two months．

B．Parents tend to think their own children grow faster than others．

C．Michel Diffre actually stayed in the cave for twenty-five days．

D．Children usually bring bad memories to their parents．

【小题4】In which column of a newspaper can we find this passage?

A．Social news	B．Community activities
C．Science	D．Children s life

There are three separate sources of danger in supplying energy by nuclear power.

First, the radioactive material must travel from its form of production to the power station. Although the power stations themselves are strongly built, the containers used for the transport of the materials are not. Normally, only two methods of transport are in use, namely road or rail. Unfortunately, both of these may have an effect on the general public, since they are sure to pass near, or even though, heavily populated areas.

Secondly, there is the problem of waste. All nuclear power stations produce waste that in most cases will remain radioactive for thousands of years. It is impossible to make these waste radioactive, and so they must be stored in one of the inconvenient ways that scientists have invented. For example, they may be buried under the ground, or dropped into deserted mines, or sunk in the sea. However, these methods do not solve the problem, since an earthquake could easily break the containers.

Third, there may occur the danger of a leak or an explosion at the power station. As with the other two dangers, this is not very likely, so it does not provide a serious objection to the nuclear program. However, it can happen.

Separately, these three types of dangers are not a great cause for worry. Taken together, though, the probability of disaster is extremely high.

1.Which of the following is FALSE ?

A．It is possible that a leak or an explosion occurs at a power station.

B．It is unusual for radioactive materials to be transported across land.

C．The containers are likely to be broken by an earthquake.

D．Nuclear wastes remain dangerous in most cases for many years.

2.The author thinks that the ways to store nuclear wastes are ____________.

A．easy

B．impossible

C．reasonable

D．ineffective

3.What do we learn from the last paragraph ?

A．The power station is a safe place.

B．The dangers of nuclear energy can be prepared.

C．The general public are strongly against the nuclear program.

D．Itself, none of the three dangers is very likely to cause much worry.

4. What is this passage mainly about ?

A．uses of nuclear power

B．Dangers from nuclear power

C．Public anger at nuclear power

D．Accidents caused by nuclear power.