单选题The reason why the laser beam is very strong is that ______.A it is artificially illuminatedB it is made up of a concentrated beam of lightC it sends out heat in all directionsD its heat is increased by the heat of the sun

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单选题

The reason why the laser beam is very strong is that ______.

it is artificially illuminated

it is made up of a concentrated beam of light

it sends out heat in all directions

its heat is increased by the heat of the sun

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第1题

CSometimes, the simplest ideas are the best. For example, to absorb heat from the sun to heat water, you need large, flat, black surfaces. One way to do that is to build those surfaces specially, on the roofs of buildings. But why go to all that trouble when cities are full of black surfaces already, in the form. of asphalt (柏油) roads?Ten years ago, this thought came into the mind of Arian de Bondt, a Dutch engineer. He finally persuaded his boss to follow it up. The result is that their building is now heated in winter and cooled in summer by a system that relies on the surface of the road outside.The heat-collector is a system of connected water pipes. Most of them run from one side of the street to the other, just under the asphalt road. Some, however, dive deep into the ground.When the street surface gets hot in summer, water pumped through the pipes picks up this heat and takes it underground through one of the diving pipes. At a depth of 100 metres lies a natural aquifer (蓄水层) into which several heat exchangers (交换器) have been built. The hot water from the street runs through these exchangers, warming the ground-water, before returning to the surface through another pipe. The aquifer is thus used as a heat store.In winter, the working system is changed slightly. Water is pumped through the heat exchangers to pick up the heat stored during summer. This water goes into the building and is used to warm the place up. After performing that task, it is pumped under the asphalt and its remaining heat keeps the road free of snow and ice.64. Which of the following is true according to the first two paragraphs?A. Arian de Bondt got his idea from his boss.B. Large, flat, black surfaces need to be built in cities.C. The Dutch engineer's system has been widely used.D. Heat can also be collected from asphalt roads.

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第2题

For what purpose are the diving pipes used?A. To absorb heat from the sun.B. To store heat for future use.C. To turn solar energy into heat energy.D. To carry heat down below the surface.

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第3题

To get some idea of the amount of heat the sun ________(1), think about this. If you ________(2)collect all the heat that hits the earth in a two-week period, it would equal the amount of all the other known sources and reserves of energy: wood, coal, and oil. But even these sources of energy depend ________(3) the sun for their formation. For example, a tree ________ (4) certainly never grow and provide fuel in the form. of wood were it not for the sun. Because the sun is so important in the production of all forms of heating fuel, more and more time and money are being spent ________(5) ways to change power from the sun directly into a form. of heat.1.A、gives offB、turns offC、takes offD、sets off2.A、willB、couldC、mustD、shall3.A、ofB、inC、onD、to4.A、willB、mustC、shallD、would5.A、studyB、studiedC、studyingD、being studying

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第4题

A laser beam can be made narrow enough to () a single cell.A.focus onB.pay attention toC.concentrate onD.lay stress on

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第5题

Spontaneous combustion is caused by ______．A.An outside heat source heating a substance until it ignitesB.Conduction of heat through a wall of material to the substanceC.Chemical action within a substanceD.All of the above

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第6题

共用题干 Heat Is Killer Extremely hot weather is common in many parts of the world.Although hot weather just makes most people feel hot,it can_______(51)serious medical problems-even death.Floods,storms,volcano eruptions and other natural______(52)kill thousands of people every year.So______(53) extreme heat.Experts say heat may be nature's deadliest killer, Recently,extreme heat was blamed ______(54)killing more than one hundred people in India.It is reported that the total heat of a hot day or several days can______(55)health.Several hot days are considered a heat wave.Experts say heat waves often become dangerous when the nighttime temperature does not_______(56)much from the highest daytime temperature.This causes great stress on the human body. Doctors say people can do many things to______(57)themselves from the dangers of extreme heat. Stay out of the sun,if possible.Drink lots of cool water.Wear light colored clothing made______(58) natural materials;avoid wearing synthetic clothing.Make sure the clothing is______(59),permitting freedom of movement.And learn the danger______(60)of the medical problems,such as headache and vomiting,that are linked to heat.Most people suffer only muscle pain as a(n)______(61)of heat stress.The fiain is a______(62)that the body is becoming too hot.Doctors say those suffering headache or muscle pain should stop all activity,rest in a cool place and drink cool liquids.Do not return to physical _______(63)for a few hours because more serious conditions could develop. Doctors say some people face an______(64)danger from heat stress.Such persons have a weak or damaged heart,high blood pressure,or other problems of the blood system. Hot Weather also increases dangers for people who must take______(65)for high blood pressure, poor blood flow,nervousness or depression.61._________A:influence B:result C:effect D:view

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第7题

共用题干 Heat Is Killer Extremely hot weather is common in many parts of the world.Although hot weather just makes most people feel hot,it can_______(51)serious medical problems-even death.Floods,storms,volcano eruptions and other natural______(52)kill thousands of people every year.So______(53) extreme heat.Experts say heat may be nature's deadliest killer, Recently,extreme heat was blamed ______(54)killing more than one hundred people in India.It is reported that the total heat of a hot day or several days can______(55)health.Several hot days are considered a heat wave.Experts say heat waves often become dangerous when the nighttime temperature does not_______(56)much from the highest daytime temperature.This causes great stress on the human body. Doctors say people can do many things to______(57)themselves from the dangers of extreme heat. Stay out of the sun,if possible.Drink lots of cool water.Wear light colored clothing made______(58) natural materials;avoid wearing synthetic clothing.Make sure the clothing is______(59),permitting freedom of movement.And learn the danger______(60)of the medical problems,such as headache and vomiting,that are linked to heat.Most people suffer only muscle pain as a(n)______(61)of heat stress.The fiain is a______(62)that the body is becoming too hot.Doctors say those suffering headache or muscle pain should stop all activity,rest in a cool place and drink cool liquids.Do not return to physical _______(63)for a few hours because more serious conditions could develop. Doctors say some people face an______(64)danger from heat stress.Such persons have a weak or damaged heart,high blood pressure,or other problems of the blood system. Hot Weather also increases dangers for people who must take______(65)for high blood pressure, poor blood flow,nervousness or depression.64._________A:impossible B:incident C:incredible D:increased

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单选题The reason why the laser beam is very strong is that ______.A it is artificially illuminatedB it is made up of a concentrated beam of lightC it sends out heat in all directionsD its heat is increased by the heat of the sun

题目内容(请给出正确答案)

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