There are two kinds of physical activity which require special training. The first demands exact careful movements of the muscles（肌肉）. This kind of activity must be strictly controlled because even a slight movement in the wrong direction will lead a mistake. To type quickly, for example, a person needs training; the slightest movement of a finger in the wrong direction may cause a spelling mistake. A dancer who has to dance on the point of her shoes or turn around on one foot must be trained for a long period of time before she can sense her own center and balance herself. You may have seen a girl walking on a rope across an empty space, which, too, requires a lot of practice.
The second kind of physical activity needs greater strength or extra effort. Most of us get tired if we try to run half a mile without stopping, but a specially-trained person can do this without much effort. Three years ago, some scientists carried out experiments, which produced meaningful and unexpected results. They wanted to find out whether a certain amount of physical exercise would injure those suffering from heart problems. They selected some male patients and trained them in continuous bicycle riding. They were surprised to find that the harmful effect of given amount of physical effort was actually less on the hearts of these trained patients than on those of the patients who were not similarly trained. This is important because it shows that regular physical exercise enables us to make better use of the oxygen（氧气）we breathe in and that this training, in fact, reduces the amount of work our hearts do. Many tasks which are hard for untrained people are not hard at all for trained people.
72．The first kind of physical activity must be strictly controlled because _________.
A．a mistake in the wrong direction is dangerous to the fingers
B．a wrong movement in a direction will cause no mistakes
C．a movement in the wrong direction will cause a mistake
D．a slight movement of a finger will lead to a mistake
73．What must a dancer do before she can balance herself?
A．She must dance on the point of her shoes. B．She must receive long-time training.
C．She must turn around on one foot. D．She must perform again and again.
74．The experiments done by some scientists showed that ________.
A．some male patients were asked to ride bicycles regularly in the experiments
B．the physical exercise had more harmful effect on the hearts of the untrained patients
C．the physical exercise was harmless to the male patients with heart trouble
D．the physical exercise could be helpful for the patients to take in more oxygen
75．What would be the best title for this text?
A．Training Our Bodies B．Physical Activities
C．Movement Training D．Extra Body Effort
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．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． |
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 |
Like many other nations, China has been busy putting together evacuation （撤侨）plans for its citizens stuck in crisis-torn Libya．The real surprise has been just how many Chinese are living there．The foreign ministry does not know for sure but puts the figure at 30-40,000．
The huge contingent （代表团） in Libya, who work for at least 27 Chinese companies, has brought to light one of the new dilemmas facing China as its economic interests expand．For a mixture of reasons that are partly political, partly business, Chinese workers are now present in many of the most unrest and dangerous parts of the world, including places where anti-Chinese sentiment over jobs and working conditions is on the rise．One of the first wake-up calls was in 2007, when a group of Chinese women were kidnapped in Pakistan, an event which led to the siege of the Red Mosque in Lahore．In the same year, nine Chinese oil workers were killed in Ethiopia．In recent years, Chinese workers have been kidnapped in Cameroon, Congo and Afghanistan．
Publicly, Chinese diplomats admit that the country needs better contingency plans to deal with this sort of situation．Privately, they worry about a different issue: that such incidents will force them to get much more involved in domestic political disputes in far-off lands, pulling the government away from its commitment to a policy of non-interference．The nightmare, a few diplomats and academics admit, would be a large, violent attack on a group of Chinese which then prompted an intense nationalist reaction at home, forcing the government to take the sort of interventionist （干涉主义的） actions it tries to shun．
Beijing gave some indication of how it will respond in the future with the decision on Thursday to send the frigate（护卫舰） Xuzhou, currently conducting anti-piracy tasks off the coast of Somalia, to Libya．Its mission will be to help the evacuation effort, but it is also a warning to any in Libya who might attack Chinese interests, as well as the latest indication of the growing global reach of China’s navy．As Andrew Erickson, a China expert at the US Naval War College says: “This latest initiative（方案） is part of a larger ongoing increase in Chinese power, presence, and influence around the world, and should come as no surprise．China has global interests, cannot free ride forever, and requires a presence in critical areas and situations in order to have a voice．”What is the main idea of the passage?
| A．There are many Chinese workers in the most unrest and dangerous parts of the world． |
| B．China should protect workers in the foreign countries． |
| C．China are taking actions to bring its citizens back from Libya． |
| D．The international situation is terrible |
The underlined word “shun” in the third paragraph most probably means?
| A．take part in | B．avoid |
| C．carry out | D．refuse |
Which of the following is NOT true according to the passage?
| A．It remains unknown how many Chinese are living in Libya． |
| B．A large number workers are working abroad, which bring about advantages and disadvantages． |
| C．In no case will the Chinese government take part in solving the political problems in far-off lands． |
| D．Our government take immediate action to deal with this sort of situation． |
What’s Not true about the frigate Xuzhou?
| A．It is conducting anti-piracy tasks off the coast of Somalia． |
| B．It will help the evacuation effort． |
| C．It is a warning to Libya who might attack Chinese interests． |
| D．It indicates that China’s navy can reach an increasing number of parts of the global． |
The huge Florida wetland known as the Everglades is a slow-moving river 80 kilometres wide but only a few centimeters deep. People call the Everglades a “river of grass” because sawgrass covers most of it. Sawgrass is not really grass. It is a plant that has leaves edged with tiny sharp teeth that can easily cut through clothes—and skin!
Travel in the Everglades is difficult. You cannot walk through shallow water because the sawgrass will cut you. The water is too shallow for regular boats. So, we use an airboat. An airboat is a flat, open boat. Like an airplane, it has a big propeller to move it. The propeller is fixed on the rear of the boat. It makes a tremendous noise, but it does the job. The boat skims along the water’s surface. Although we can still get lost in an airboat, at least we are above the alligators(短吻鳄).
While hundreds of different kinds of animals live in the Everglades, the most famous is surely the alligator. Once endangered, alligators are now protected within Everglades National Park. Visitors are likely to see them both on land and in water.
For a long time, dangers have threatened the Everglades. Around 1900, some people felt this precious wetland should be drained (排干). They said it was just a big swamp and not good for anything. In the 1920s, there was a land boom in Florida. People wanted to build homes everywhere, including in the Everglades. They built canals, levees (防洪堤), and other water systems that stopped the rivers flowing into the Everglades. Factories were built near rivers that flowed into the wetland. These factories dumped poisonous waste that damaged the Everglades ecosystem.
People are now working to preserve the Everglades National Park for the future. Right now, one big problem is the paperbark tree. This tree is an invader from Australia.
Paperbark trees soak up a lot of water. In the early 1900s, people brought them to Florida because they thought they would help drain the Everglades. However, the invaders adapted too well. Paperbark trees have taken over hundreds of thousands of acres of the Everglades and killed other trees. Scientists are cutting down these invaders or spraying them with herbicides (除草剂) to kill them.Which helps to explain why it is difficult to travel in Everglades?
| A．Airboats may make a very big noise. |
| B．You may get lost when passing through. |
| C．Paperbark trees soak up too much water there. |
| D．Many different kinds of animals are to be protected. |
Why do people use airboats instead of normal boats?
| A．They have big propellers to move them faster than alligators. |
| B．The propeller makes loud noise so as to scare alligators. |
| C．Their flat bottom can skim along the water surface. |
| D．They can watch alligators without hurting them. |
The following measures were taken to drain the Everglades except that people______.
| A．built canals and levees to stop the rivers flowing into Everglades |
| B．built factories near rivers that flowed into the wetland |
| C．brought Paperbark to soak up water in Everglades |
| D．are cutting down these Paperbark trees |
The underlined word "invader" probably means something______.
| A．that moves in from another place |
| B．that enters and takes control |
| C．that has been brought in |
| D．that is in danger |
That “Monday morning feeling” could be a crushing pain in the chest which leaves you sweating and gasping for breath. Recent research from Germany and Italy shows that heart attacks are more common on Monday mornings and doctors blame the stress of returning to work after the weekend break.
The risk of having a heart attack on any given day should be one in seven, but a six-year study helped by researchers at the Free University of Berlin of more than 2,600 Germans showed that the average person had a 20 per cent higher chance of having a heart attack on a Monday than on any other day.
Working Germans are particularly not protected against attack, with a 33 per cent higher risk at the beginning of the working week. Non-workers, by comparison, appear to be no more at risk on a Monday than any other day.
A study of 11,000 Italians proved 8 am on a Monday morning as the most stressful time for the heart, and both studies showed that Sunday is the least stressful day, with fewer heart attacks in both countries.
The findings could lead to a better understanding of what is the immediate cause of heart attacks, according to Dr Stefan Willich of the Free University. “We know a lot about long-term risk factors such as smoking and cholesterol（胆固醇）but we don’t know what actually causes heart attacks, so we can’t give clear advice on how to prevent them,” he said.
Monday mornings have a double helping of stress for the working body as it makes a rapid change from sleep to activity, and from the relaxing weekend to the pressures of work.
“When people get up, their blood pressure and heart rate go up and there are hormonal（内分泌）changes in their bodies,” Willich explained. “All these things can have an unfavourable effect in the blood system and increase the risk of a clot（血凝块）in the arteries（动脉）which will cause a heart attack.”
“When people return to work after a weekend off, the pace of their life changes. They have a higher workload, more stress, more anger and more physical activity,” said Willich.Monday morning feeling, as this passage shows, .
| A．is not so serious as people thought |
| B．is harmful to working people in developed countries. |
| C．is the first killer in Germany and Italy. |
| D．is created by researchers in Germany and Italy |
To protect people from suffering from heart attack, doctors have paid much attention to.
| A．people’s working time |
| B．people’s living place |
| C．people’s diet and lifestyle |
| D．people’s nationalities |
It can be learned from this passage that heart attack has nothing to do with.
| A．blood pressure | B．heart rate |
| C．hormonal changes | D．blood group |
If the researchers give us some advice to avoid Monday morning feeling, what might it be?
| A．Stop working on Monday |
| B．Create a pleasant working environment |
| C．Get up late on Monday morning |
| D．Go to work with a doctor |
Science is a dominant theme in our culture. Since it touches almost every aspect of our life, educated people need at least some idea of its structure and operation. They should also have an understanding of the subculture in which scientists live and the kinds of people they are. An understanding of general characteristics of science as well as specific scientific concepts is easier to obtain if one knows something about the things that excite and frustrate the scientist.
This book is written for the intelligent student or lay (外行) person whose knowledge of science is superficial; for the person who has been presented with science as a musty storehouse of dried facts; for the person who sees the chief objective of science as the production of small devices; and for the person who views the scientists as some sort of magician.
The book can be used to supplement a course in any science, to accompany any course that attempts to give an understanding of the modern world, or independently of any course, simply to provide a better understanding of science. We hope this book will lead readers to a broader perspective on scientific attitudes and a more realistic view of what science is, who scientists are, and what they do.
It will give them an awareness and understanding of the relationship between science and our culture and an appreciation of the roles science may play in our culture. In addition, readers may learn to appreciate the relationship between scientific views and some of the values and philosophies that are widespread in our culture.
We have tried to present in this book an accurate and up-to-date picture of the scientific community and the people who populate it. That population has in recent years come to consist of more and more women. This increasing role of women in the scientific subculture is not an unique incident but, rather, part of the trend evident in all parts of society as more women enter traditionally male-dominated fields and make significant contributions.
In discussing these changes and contribution, however, we are faced with a language that is somewhat sexist, one that uses male nouns or pronouns in referring to unspecified individuals. To balance this built-in bias (倾向), we have adopted the policy of using plural nouns and pronouns whenever possible and , when absolutely necessary, alternating him and her.
This policy is far from being ideal, but it is at least an acknowledgement of the inadequacy of our language in treating half of the human race equally.
We have also tried to make the book entertaining as well as informative. Our approach is usually informal. We feel, as many other scientists do, that we shouldn’t take ourselves too seriously. As the reader may observe, we see science as a delightful pastime rather than as a grim and dreary way to earn a living.According to the passage, ‘scientific subculture’ means __________.
| A．cultural groups that are formed by scientists. |
| B．people whose knowledge of science is very limited |
| C．the scientific community |
| D．people who make good contribution to science |
We need to know something about the structure and operation of science because_______.
| A．it is not easy to understand the things that excite and frustrate scientists. |
| B．science affects almost every aspect of our life. |
| C．scientists live in a specific subculture. |
| D．it is easier to understand general characteristics of science. |
The book mentioned in this passage is written for readers who __________.
| A．are intelligent college students and lay person who do not know much about science. |
| B．are good at producing various devices |
| C．work in a storehouse of dried facts |
| D．want to have a superficial understanding of science. |
According to this passage, ______________.
| A．English is a language full of sexual discrimination. |
| B．only in the scientific world is the role of women increasing rapidly. |
| C．women are making significant contributions to eliminating the inadequacy of our language. |
| D．male nouns or pronouns should not be used to refer to scientists. |