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Thousands of people perished in the storm.
A．died
B．suffered
C．floated
D．scattered
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更多 “ Thousands of people perished in the storm.A．diedB．sufferedC．floatedD．scattered ” 相关考题
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Many scientists have been probing psychological problems.A．solvingB．exploringC．settlingD．handling
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Electromagnetic EnergyWhite light seems to be a combination of all colors. The energy that comes from a source of light is not limited to the kind of energy you can see. Heat is given off by a flame or an electric light. On a cloudy day it is possible to get a sunburn even though you feel cool. Visible light and the kind of energy that produce warmth and sunburn are examples of electromagnetic energy.The sun is 93 million miles from the earth. Yet we can use energy from the sun because electromagnetic energy travels through space.Many other kinds of energy are also types of electromagnetic energy. Radio, television, and radar signals travel from transmitters to receivers as low-energy electromagnetic waves. Infrared (红外线的) radiation is an electromagnetic wave. When it is absorbed by matter, heat is produced. Waves of infrared and visible light have more energy than waves of radio, television, or radar. Ultraviolet rays (紫外线) and X-rays are electromagnetic waves with even greater amounts of energy. Infrared radiation is used in cooking food and heating buildings. Sunlight and electric lights are part of our requirements for normal living. Ultraviolet radiation is useful in killing certain disease organisms. X-rays and gamma rays have so mush energy that they travel right through solid objects. They can be used to detect and treat cancer. X-rays are used in industry to find hidden cracks in metal, and in medicine to reveal broken bones.Usually we use electricity to generate electromagnetic energy. The source of most of our energy is the sun. Heat from the sun causes water to evaporate. When the water falls to the earth as rain, some of it is trapped behind dams and then used to operate electric generators. Other generators are powered by coal, but the energy stored in coal came from the sun, too.Until recently, the source of the tremendous amount of energy given off by the sun was a puzzle. If the sun depended on chemical reactions, it would have used up all its energy long ago. Experiments with electromagnetic radiation led to the theory that mass can be converted into energy. About forty years after the theory was proposed, nuclear energy was harnessed (利用) by man. Chemical energy comes from electron (电子) rearrangement. Nuclear energy comes from a change in the nucleus of an atom. Compared with chemical reactions, nuclear reactions release millions of times more energy per pound of fuel. We now believe that the sun's energy comes from the nuclear reactions in which hydrogen is changed into helium(氦).Nuclear energy is beginning to compete with coal as an economical source of power to generate electricity. It is also being used to operate engines in large ships. Scientists continue to seek new and better methods of obtaining and using energy.A. Nuclear Reactions as the Lasting Source of the Sun's EnergyB. The Most Important Source of EnergyC. Types of Electromagnetic EnergyD. X-rays Are Used to Detect and Treat Cancer.E. Seeking New Sources of EnergyF. Nuclear Energy is Beginning to Compete with CoalParagraph 3 ______
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Smart WindowWindows not only let light in to cut down an electricity use for lighting, but the light coming through the window also provides heat. However, windows are not something people typically associate with being a cutting edge technology. Researchers are now working on new technologies that enable a window to quickly change from clear to dark and anywhere in between with a flip of a switch."It took us a long time to figure out what a window really is," says Claes Granqvist. He's a professor of solid-state physics at Uppsala University in Sweden. "It's contact with the outside world. You have to have visual contact with the surrounding world to feel well. " So, windows and natural light are important for improving the way people feel when they're stuck indoors.Yet, windows are the weak link in a building when it comes to energy and temperature control. In the winter, cold air leaks in. When it's hot and sunny, sunlight streams in. All of this sunlight carries lots of heat and energy. And all of this extra heat forces people to turn on their air conditioners. Producing blasts of cold air, which can feel so refreshing, actually suck up enormous amounts of electricity in buildings around the world.Windows have been a major focus of energy research for a long time. Over the years, scientists have come up with a variety of strategies for coating, glazing, and layering windows to make them more energy efficient. Smart windows go a step further. They use chromogenic technologies which involve changes of color.Electrochromic windows use electricity to change color. For example, a sheet of glass coated with thin layers of chemical compound such as tungsten oxide works a bit like a battery. Tungsten oxide is clear when an electric charge is applied and dark when the charge is removed, that is, when the amount of voltage is decreased, the window darkens until it's completely dark after all electricity is taken away. So applying a voltage determines whether the window looks clear or dark.One important feature that makes a smart window so smart is that it has a sort of "memory. " All it takes is a small jolt of voltage to turn the window from one state to the other. Then, it stays that way. Transitions take anywhere from 10 seconds to a few minutes, depending on the size of the window. The development of smart windows could mean that massive air conditioning systems may no longer need. "In the future," Granqvist says, "our buildings may look different. "Which of the following statements does not indicate the importance of windows as described in the first two paragraphs?A．Windows can change from clear to dark to save energy.B．Windows help to save energy by letting light in.C．Windows help to save energy by providing heat.D．Windows enable people to have contact with the outside world.
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Sperm whales can produce stronger ultrasonic waves to kill their prey than dolphins.A．RightB．WrongC．Not mentioned
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In Britain and many other countries appraisal is now a tool of management.A．evaluationB．efficiencyC．productionD．publicity
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And the cars are tested for defects before leaving the factory.A．functionsB．faultsC．motionsD．parts
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For young children, getting dressed is a complicated business.A．strangeB．complexC．personalD．funny
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