题目内容

Scientists have searched for many years for a method to tell whether a volcano(火山)explosion will be small or large. Now, four scientists say they have discovered something in lava(熔岩)that will help do this. They did the research on Mount Unzen on the southern Japanese island of Kyushu.

Mount Unzen exploded in November, 1990. Since then, more explosions have killed 43 people and destroyed the homes of more than 2,000 others. The volcano is still active today.

The scientists say the lava of the volcano contains high level of an element(成份),which is a sign of the presence of the lava from deep in the earth, not from the surface. They say it shows that the lava coming directly from inside the earth is connected with huge explosions instead of smaller ones.

The scientists examined the lava from 18 explosions of Mount Unzen that took place during many thousands of years. They also studied the lava from other volcanoes in the area that are older than Mount Unzen. The lava studied came from both large and small explosions. The scientists found that large explosions contained more of the element than small ones. The scientists say if they had known this two years earlier, they could have warned the people living in the area near Mount Unzen and saved many lives.

56. Scientists have searched for a long time in order to ______.

A. tell whether a volcano explosion will be small or large

B. tell whether a volcano explosion will be worthy or not

C. tell the number of active volcanoes in the world

D. find if there is any volcano in Japan

57. From the passage we learn that Mount Unzen is the name of ______.

A. an active volcano

B. a Japanese island

C. a huge volcano explosion

D. a kind of lava

58. Where does lava come from?

A. It comes from the deepest part of the ocean.

B. It comes from the earth surface.

C. Not mentioned in the passage.

D. It is from deep part in the earth.

59. The four scientists discovered that the level of the element contained in the lava could tell ______.

A. the place of a possible explosion

B. the degree of a volcano explosion

C. the number of volcano explosions

D. the time of a possible explosion

60. The research of the four scientists was based on ______.

A. the lava from different explosions in the area

B. the presence of the lava from the surface

C. the damages caused by the 1990 explosion

D. the lava that caused explosions

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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 / 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.

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.

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.

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.

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.

The text is most probably a ________.

A. science news report  B. book review

C. newspaper ad    D. science fiction story

PART FOUR   WRITING (45%)

    People diet to look more attractive. Fish diet to avoid being beaten up, thrown out of their social group, and getting eaten as a result. That is the fascinating conclusion of the latest research into fish behavior by a team of Australian scientists.

The research team have discovered that subordinate fish voluntarily diet to avoid challenging their larger competitors. “In studying gobies we noticed that only the largest two individuals, a male and female, had breeding(繁殖) rights within the group," explains Marian Wrong. “All other group members are nonbreeding females, each being 5-10% smaller than its next largest competitor. We wanted to find out how they maintain this precise size separation."

The reason for the size difference was easy to see. Once a subordinate fish grows to within 5-10% of the size of its larger competitor, it causes a fight which usually ends in the smaller goby being driven away from the group. More often than not, the evicted fish is then eaten up.

It appeared that the smaller fish were keeping themselves small in order to avoid challenging the boss fish. Whether they did so voluntarily, by restraining how much they ate, was not clear. The research team decided to do an experiment. They tried to fatten up some of the subordinate gobies to see what happened. To their surprise, the gobies simply refused the extra food they were offered, clearly preferring to remain small and avoid fights, over having a feast.

 The discovery challenges the traditional scientific view of how boss individuals keep their position in a group. Previously it was thought that large individuals simply used their weight and size to threaten their subordinates and take more of the food for themselves, so keeping their competitors small.

While the habits of gobies may seem a little mysterious. Dr. Wong explains that understanding the relationships between boss and subordinate animals is important to understanding how hierarchical(等级的) societies remain stable.

The research has proved the fact that voluntary dieting is a habit far from exclusive to human.”As yet, we lack a complete understanding of how widespread the voluntary reduction of food intake is in nature," the researchers comment. “Data on human dieting suggests that, while humans generally diet to improve health or increase attractiveness, rarely does it improve long-term health and males regularly prefer females that are fatter than the females' own ideal."

65 When a goby grows to within 5-10% of the size of its larger competitor, it ______.

A. faces danger       B. has breeding rights

C. eats its competitor     D. leaves the group itself

66. The underlined words “the evicted fish" in Paragraph 3 refer to _____.

A. the fish beaten up       B. the fish found out

C. the fish fattened up     D. the fish driven away

67 The experiment showed that smaller fish ____.

A. fought over a feast        B. went on diet willingly

C. preferred some extra food  D. challenged the boss fish

68. What is the text mainly about?

A. Fish dieting and human dieting.

B. Dieting and health.

C. Human dieting.

D. Fish dieting. 

What makes a person a scientist? Does he have ways or tools of learning that are different from those of others??The answer is“no”.It isn't the tools a scientist uses but how he uses these tools which makes him a scientist .You will probably agree that knowing how to use a power is important to a carpenter(木匠).You will probably agree,too, that knowing how to investigate(调查),how to discover information ,is important to everyone. The scientist ,however ,goes one step further ;he must be sure that he has a reasonable answer to his questions and that his answer he gets to many questions is into a large set of ideas about how the world works.?

The scientist's knowledge must be exact .There's no room for half right or right just half the time. He must be as nearly right as the conditions permit .What works under one set of conditions at one time must work under the same conditions at other times. If the conditions are different ,any changes the scientist observes in a demonstration(实证)must be explained by the changes in the conditions. This is one reason why investigations are important in science .Albert Einstein ,who developed the Theory of Relativity ,arrived at this theory through mathematics. The accuracy(正确性)of his mathematics was later tested through investigation. Einstein's ideas were proved to be correct .A scientist uses many tools for measurements .Then the measurements are used to make mathematical calculations(计算)that may test his investigations.

1.What makes a scientist according to the passage??

A.The tools he uses.

B.His ways of learning.?

C.The way he uses his tools.

D.The various tools he uses.?

2.“...knowing how to investigate ,how to discover information ,is important to everyone.”The writer says this to show_______.?

A.the importance of information

B.the difference between scientists and ordinary people?

C.the importance of thinking

D.the difference between carpenters and ordinary people?

3.A sound scientific theory should be one that_______.?

A.works under one set of conditions at one time and also works under the same conditions at other times?

B.leaves no room for improvement?

C.doesn't allow any change even under different conditions?

D.can be used for many purposes?

4.What is the main idea of the passage??

A.Scientists are different from ordinary people.?

B.The Theory of Relativity.?

C.Exactness is the core(核心)of science.?

D.Exactness and way of using tools are the keys to making of a scientist.?

 

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