题目内容
（请给出正确答案）
What causes power failure？
A．Excessive use.
B．Lack of demand.
C．Increased supply.
D．Poor quality fans.
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更多“What causes power failure？A．Ex…”相关的问题
What were the causes of the War of Independence？
A．The development of colonial economy led to demand for more power to determine their own business.
B．The cruel exploitation of the colonies by the British government.
C．The sale of tea in the colonies.
D．Both A and B
Power seekers strive hard to 【C5】______ positions where they can 【C6】______ authority 【C7】______ large numbers of people.
Individual performers who lack this 【C8】______ are not likely to 【C9】______ far up the managerial ladder. They usually scorn company politics and 【C10】______ their energies to other types of activities. The power 【C11】______ is part of management, and it is played best by those who enjoy it 【C12】______ .
One of the least rational 【C13】______ of business organizations is that of 【C14】______ managers who have a 【C15】______ need to exercise authority, and then teaching them that authoritative 【C16】______ are wrong and that they should be consultative or participative. It is a serious mistake to teach managers that they should 【C17】______ styles that are inconsistent 【C18】______ their unique personalities. Yet this is precisely what a large number of business organizations are doing; and it explains, 【C19】______, why their management development programs are not 【C20】______ .
【C1】
A．move
B．motive
C．exercise
D．objective
Causal reasoning may go from cause to effect or from effect to cause. Either way, we reason from what we know to what we want to find out. Sometimes we reason from an effect to a cause and then on to another effect. Thus, if we reason that because the lights have gone out, the refrigerator won't work, we first relate the effect (lights out) to the cause (power off) and then relate that cause to another effect (refrigerator not working). This kind of reasoning is called, for short, effect to effect. It is quite common to reason through an extensive chain of causal relations. When the lights go out we might reason in the following causal chain: lights out — power off — refrigerator not working — temperature will rise — milk will sour. In other words, we diagnose a succession of effects from the power failure, each becoming the cause of the next.
Causes are classified as necessary, sufficient, or contributory. A necessary cause is one which must be present for the effect to occur, as combustion is necessary to drive a gasoline engine. A sufficient cause is one which can produce an effect unaided, though there may be more than one sufficient cause: a dead battery is enough to keep a car from starting, but faulty spark plugs, or an empty gas tank will have the same effect. A contributory cause is one which helps to produce an effect but cannot do so by itself, as running through a red light may help cause an accident, though other factors — pedestrians or other cars in the intersection — must also be present.
In establishing or refuting a causal relation it is usually necessary to show the process by which the alleged cause produces the effect. Such an explanation is called a causal process.
What the author discussed in the previous section is most probably about ______.
A．relationships between causes and results
B．classification of reasoning
C．some other common types of reasoning
D．some special type of reasoning
听力原文： Sports can help you keep fit and get in touch with nature. However, whether you are on the mountains, in the waves, or on the grassland, you should be aware that your sport of choice might have great influence on the environment.
Some sports are resource-hungry. Golf, as you may know, eats up not only large areas of countryside, but also tons of water. Besides, all sorts of chemicals and huge amounts of energy are used to keep its courses in good condition. This causes major environmental effects. For example, in the dry regions of Portugal and Spain, golf is often held responsible for serious water shortage in some local areas.
There are many environment-friendly sports. Power walking is one of them that you could take up today. You don't need any special equipment except a good pair of shoes; and you don't have to worry about resources and your purse. Simple and free, power walking can also keep you fit. If you walk regularly, it will be good for your heart and bones. Experts say that 20 minutes of power walking daily can make you feel less anxious, sleep well and have better weight control.
Whatever sport you take up, you can make it greener by using environment-friendly equipment and buying products made from recycled materials. But the final goal should be "green gyms". They are better replacements for traditional health clubs and modern sports centers. Members of green gyms play sports outdoors, in the countryside or other open spaces. There is no special requirement for you to start your membership. And best of all, it's free.
Questions 29 to 32 are based on the passage you have just heard.
29. Which is the speaker most probably in favor of？
30. What do we know about golf from the passage？
31. Why does the speaker use power walking as an example？
32. What is the speaker's main purpose of giving this speech？
(33)
A．Cycling around a lake.
B．Motor racing in the desert.
C．Playing basketball in a gym.
D．Swimming in a sports center.
Progressives tried to resolve these problems by organizing ideas and actions around three basic themes. First, they sought to end abuses of power. Second, progressives aimed to replace corrupt power with the power of reformed institutions such as schools, charities, medical clinics, and the family. Third, progressives wanted to apply principles of science and efficiency on a nationwide scale to all economic, social, and political institutions, to minimize social and economic disorder and to establish cooperation, especially, between business and government, that would end wasteful competition and labor conflict.
Befitting their name, progressives had strong faith in the ability of humankind to create a better world. More than ever before, Americans looked to government as an agent of the people that could and should intervene in social and economic relations to protect the common good and substitute public interest for self-interest.
The passage is primarily concerned with ______.
A．the reasons for the Progressive Movement
B．the problems that American society faced between the 1890s and the end of World War I
C．the causes and contents of the Progressive reform
D．the belief that Americans possessed in their society
What is the substance in cigarettes that causes cancer？
A．Cigarette ashes.
B．Nicotine.
C．Tar.
D．Not mentioned here.
Solar Power without Solar Cells
A dramatic and surprising magneticeffect of light discovered by University of Michigan1researcherscould lead to solar power without traditional semiconductor-based solar cells.The researchers found a way to make an“optical51 ,” said Stephen Rand, a professor in thedepartments of Electrical Engineering and Computer Science, Physics and AppliedPhysics.
Light has electric and magnetic52 .Until now, scientists thought the effect of the magnetic field were so weakthat they could be 53 . What Rand and his colleagues found isthat at the right intensity, when light is traveling through a material thatdoes not 54 electricity, the light field cangenerate magnetic effects that
are 100 million times stronger than previouslyexpected. Under these circumstances, the magnetic effects develop strength55 toa strong electric effect.
“This could lead to a new kind of solarcell without semiconductors and without absorption to produce charge separation,” Rand said. “In solar cells, the 56 goesinto a material, gets absorbed and creates heat. Here, we expect to have a verylow heat load2. Instead of the light being absorbed, energy is stored in themagnetic moment3. Intense magnetization can be induced by intense light andthen it is ultimately capable of providing a capacitive power 57 Whatmakes this possible is a previously undetected brand of “opticalrectification,” says William Fisher, a doctoral student in applied physics. Intraditional optical rectification, light's electric field causes a chargeseparation, or a pulling58of the positive and negative charges ina material. This sets up a voltage, similar to59in a battery.
Rand and Fisher found that under the rightcircumstances and in right types of materials, the light's magnetic field canalso create optical rectification. The light must be shone througha 60 thatdoes not conduct electricity, such as glass. And it must be focused to anintensity of 10 million watts per square centimeter8. Sunlight isn't this61 onits own, but new materials are being sought that would work at lowerintensities, Fisher said.
“In our most recent paper, we show thatincoherent light9 like sunlight is theoretically almost62effectivein producing charge separation as laser light is,” Fisher said.
This new63 couldmake solar power cheaper, the researchers say. They predict that with improvedmaterials they could achieve 10 percent efficiency in converting solar power touseable energy. That's equivalent to today's commercial-grade solar cells.
“To manufacture modem solar cells, youhave to do64 semiconductor processing,” Fisher said.“All we would need are lenses to focus the light and a fiber to guide it. Glassworks for65 .It's already made in bulk, and itdoesn't require as much processing. Transparent ceramics might be even better.”
51.A.disc
B.fiber
C.instrument
D.battery
What is the best title for this passage？
A．The Causes of Industrial Revolution.
B．The Industrial Revolution and Its Significance.
C．The Theory of Division of Labour and Its Significance.
D．Adam Smith, the Economist and Philosopher.
What causes the tension that draws water up a plant？
A．Humidity
B．Plant growth
C．Root pressure
D．Evaporation
