题目内容

What Is the Coolest Gas in the Universe What is the coldest air temperature ever recorded on the earth Where was this low temperature recorded The coldest recorded temperature on Earth was -91℃, which 1 in Antarctica in 1983. We encounter an interesting situation when we discuss temperatures in 2 temperatures in Earth orbit actually range from about 20℃ to 120℃. The temperature depends upon 3 you are in direct sunlight or shade. Obviously, -120℃ is colder than our body can safely endure. Thank NASA science for well-designed space 4 that protect astronauts from these temperature extremes. The space temperatures just discussed affect only our areal of the solar 5 . Obviously, it is hotter closer to the sun and colder as we travel away from the sun. Astronomers estimate temperatures at Pluto are about -210℃. How cold is the lowest estimated temperature in the entire universe Again, it depends upon your 6 . We are taught it is supposedly 7 to have a temperature below absolute zero, which is -273℃, at which atoms do not move. Two scientists, whose names are Cornell and Wieman, have successfully cooled down a gas to a temperature barely 8 absolute zero. They won the Nobel Prize in Physics in 2001 for their work—not a discovery, in this case. Why is the two scientists’ work so important to science In the 1920s, Satyendra Nath Bose was studying an interesting 9 about special light particles we now call photons. Bose had trouble 10 other scientists to believe his theory, 11 he contacted Albert Einstein. Einstein’s calculations helped him theorize that atoms 12 behave as Bose thought—but only at very cold temperatures. Scientists have also discovered that 13 atoms can help them make the world’s atomic docks even more accurate. These clocks are so accurate today they would only lose one second 14 six million years! Such accuracy will help us travel in space because distance is velocity times time (d=v×t). With the long distances involved in space 15 , we need to know time as accurately as possible to get accurate distance.

A. above
B. below
C. within
D. beyond

查看答案
更多问题

Old Man Myths and Realities 1. When does a middle-aged man become an old man Officially, of course, it’s when we reach retirement age. But, as we all know, this is a fairly blunt (生硬的) method of decision making. As life expectancy (预期寿命) increases, retirement planning needs to be changed. This is because being an old man today is very different from what it was a generation or so ago. 2. Sixty-five is the new middle-aged man. These days people are talking about the young-old, that is ages 70 to 75, and those over 75 as the old-old. The young-old frequently continue in good health and maintain strong links with friends and family. The old-old have a much higher chance of poor health and social isolation. 3. Although men are living longer, there are still more old women than old men. This fact alone should arouse interest as to why. Relatively little is actually known about why this is the case or about the experiences of the old man. Sure, we are aware that the old man experiences anxiety, financial problems, loneliness, etc, but that’s really about all we know. 4. It is usually believed that the old man often complains about their health. In fact, most old man think their health is good even though most are diagnosed with at least one chronic illness. The physical health of the old man is strongly affected by their health behavior when they were younger. A. New Definitions of the Old Man B. Changing Concept of the Old Man C. Health of the Old Man D. Happy Old Man and Sad Old Man E. Limited Knowledge of the Old Man’s Experiences F. Contempt for the Old Man A. in good health B. in the past C. in the wrong D. the old man E. a middle-aged man F. a young man Nowadays men generally live longer than ______.

Preserving Nature for Future Demands for stronger protection for wildlife in Britain sometimes hide the fact that similar needs are felt in the rest of Europe. Studies by the Council of Europe, of which 21 countries are members, have shown that 45% of reptile (爬行动物) species and 24% of butterflies (蝴蝶) are in danger of dying out. European concern for wildlife was outlined by Dr. Peter Baum, an expert in the environment and natural resources division of the council, when he spoke at a conference arranged by the administrators of a British national park. The park is one of the few areas in Europe to hold the council’s diploma (证书) for nature reserves (自然保护区) of the highest quality, and Dr. Baum had come to present it to the park once again. He was afraid that public opinion was turning against national parks, and that those set up in the 1960s and 1970s could not be set up today. But Dr. Baum clearly remained a strong supporter of the view that natural environments needed. To be allowed to survive in peace in their own right. "No area could be expected to survive both as a true nature reserve and as a tourist attraction", he went on. The short sighted view that reserves had to serve immediate human demands for outdoor recreation (户外娱乐) should be replaced by full acceptance of their importance as places to preserve nature for the future. "We forget that they are the guarantee of life systems, on which any built-up area ultimately depends," Dr. Baum went on. "We could manage without most industrial products, but we could not manage without nature. However, our natural environment areas, which are the original parts of our countryside, have shrunk (缩小) to become mere islands in a spoiled and highly polluted Landmass." Which of the following can be inferred from the last paragraph

A. We have developed industry at the expense of countryside.
B. We have forgotten what our original countryside looked like.
C. People living on islands should protect natural resources for their survival.
D. We should destroy all the built up areas.

A Sunshade for the Planet Even with the best will in the world, reducing our carbon emissions is not going to prevent global warming. It has become clear that even if we take the most strong measures to control emissions, the uncertainties in our climate models still leave open the possibility of extreme warming and rises in sea level. At the same time, resistance by governments and special interest groups makes it quite possible that the actions suggested by climate scientists might not be implemented soon enough. Fortunately, if the worst comes to the worst, scientists still have a few tricks up their sleeves. For the most part they have strongly resisted discussing these options for fear of inviting a sense of complacency that might thwart efforts to tackle the root of the problem. Until now, that is. A growing number of researchers are taking a fresh look at large-scale "geoengineering" projects that might be used to counteract global warming. "I use the analogy of methadone," says Stephen Schneider, a climate researcher at Stanford University in California who was among the first to draw attention to global warming. "If you have a heroin addict, the correct treatment is hospitalization, and a long rehab. But if they absolutely refuse, methadone is better than heroin." Basically the idea is to apply "sunscreen" to the whole planet. One astronomer has come up with a radical plan to cool the earth; launch trillions of feather-light discs into space, where they would form a vast cloud that would block the sun’s rays. It’s controversial, but recent studies suggest there are ways to deflect just enough of the sunlight reaching the earth’s surface to counteract the warming produced by the greenhouse effect. Global climate models show that blocking just 1.8% of the incident energy in the sun’s rays would cancel out the warming effects produced by a doubling of greenhouse gases in the atmosphere. That could be crucial, because even the most severe emissions- control measures being proposed would leave us with a doubling of carbon dioxide by the end of this century, and that would last for at least a century more. What is NOT true of the effectiveness of "sunscreen", according to the last paragraph

A. It deflects sunlight reaching the earth to counteract the warming.
B. It blocks the incident energy in the sun’s rays.
C. It is a controversial method.
D. It decreases greenhouse gases in the atmosphere.

What Is the Coolest Gas in the Universe What is the coldest air temperature ever recorded on the earth Where was this low temperature recorded The coldest recorded temperature on Earth was -91℃, which 1 in Antarctica in 1983. We encounter an interesting situation when we discuss temperatures in 2 temperatures in Earth orbit actually range from about 20℃ to 120℃. The temperature depends upon 3 you are in direct sunlight or shade. Obviously, -120℃ is colder than our body can safely endure. Thank NASA science for well-designed space 4 that protect astronauts from these temperature extremes. The space temperatures just discussed affect only our areal of the solar 5 . Obviously, it is hotter closer to the sun and colder as we travel away from the sun. Astronomers estimate temperatures at Pluto are about -210℃. How cold is the lowest estimated temperature in the entire universe Again, it depends upon your 6 . We are taught it is supposedly 7 to have a temperature below absolute zero, which is -273℃, at which atoms do not move. Two scientists, whose names are Cornell and Wieman, have successfully cooled down a gas to a temperature barely 8 absolute zero. They won the Nobel Prize in Physics in 2001 for their work—not a discovery, in this case. Why is the two scientists’ work so important to science In the 1920s, Satyendra Nath Bose was studying an interesting 9 about special light particles we now call photons. Bose had trouble 10 other scientists to believe his theory, 11 he contacted Albert Einstein. Einstein’s calculations helped him theorize that atoms 12 behave as Bose thought—but only at very cold temperatures. Scientists have also discovered that 13 atoms can help them make the world’s atomic docks even more accurate. These clocks are so accurate today they would only lose one second 14 six million years! Such accuracy will help us travel in space because distance is velocity times time (d=v×t). With the long distances involved in space 15 , we need to know time as accurately as possible to get accurate distance.

A. reasonable
B. wonderful
C. impossible
D. necessary

答案查题题库