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A．calling people's attention to the true value of water
B．blowing up dams that affect the supply of fresh water
C．adopting sound water conservation policies
D．finding the best way to distribute the world's water
答案
更多“To solve the water supply problem the world today faces, the author suggests at the end of”相关的问题
第1题
Archimedes is well-known for one specific (精确的) idea that he came up with. "Archime des' principle" tells us that a solid object which is immersed in a liquid is pushed up by a force which is equal to the weight of the water that moves. For example, if you put a piece of wood and a piece of metal of the same size in water, only the wood will float. Both the wood and metal move the same amount (量) of water, but the water moved by the wood weighs less than that of the water moved by the gold. It is believed that Archimedes discovered this principle when the King of Syracuse asked him to solve a problem. The King wanted to know if his crown (皇冠) was pure gold or a mixture of gold and silver. The King, of course, did not want to melt his crown to find out. The idea came to Archimedes as he lowered himself into his bath. He noticed how the water spilled out of the tub. He decided to use the same idea for the crown. He knew that a gold crown immersed in water would weigh more than the one made of silver. The experiment was done and the goldsmith was proved guilty of trying to cheat the King.
The best title for this passage is ______
A．Archimedes
B．Archimedes's principle
C．A Gold and Silver Crown
D．The King of Syracuse
第2题
A．Y
B．N
C．NG
第3题
A．emphasized
B．delivered
C．paid
D．focused
第4题
听力原文： The year is 2501, and the Earth is desperately short of fuel. All Earth's coal, oil and wood have been used up long ago, and scientists have been sent to the ends of the universe in search of alternative forms of energy.
A rich and powerful civilization has been discovered on the planet Jupiter, and Earth is supplied with fuel by constant supply fleets from that planet, but the price is very high. Unless it discovers an alternative source of energy soon, civilization on Earth will fail, and its inhabitants will have to move to other planets where they will be little more than slaves. Then Jupiter will take possession of Earth-- the most beautiful, most desirable planet in the universe.
Human scientists have been sure for a long time that Jupiter possesses a method of creating constant energy and now ten explorers on a secret mission from Earth have discovered the secret--a kind of heavy, green dust which will change salt water to high grade petroleum. This dust covers a large part of Jupiter's surface, and just a few pounds of it could solve the world's energy crisis since it would reproduce itself continuously in Earth's atmosphere.
(23)
A．Explorers.
B．Doctors.
C．Teachers.
D．Coal-miners.
第5题
The purpose of the passage is to______.
A．alert the reader to reduce the water use
B．explain the industrial uses of water
C．acquaint the reader with water pollution problems
D．demonstrate various measures to solve the pollution problem
第6题
Questions 26 to 30 are based on the following passage:
Over vast areas of every continent,the rainfall and vegetation necessary for life are disappearing.Already more than 40 percent of the earth's land is desert or desertlike.About 628 million people—one out of seven—live in these dry regions.In the past,they have managed to survive,but with difficulty.[ZZ(Z]Now largely through problems caused by modern life,their existence is threatened by the slow,steady spread of the earth's deserts. Scientists still do not understand all the complex problems of the desert,but there have been many ideas for saving the land.Sandi Arabia has planted 10 million trees to help keep the sand from taking over fertile areas.The Israelis are aga in using some of the water collection systems left by the ancient people in the Negev desert.They plan to water their orchards with the extra water.Some Sahel farmers still raise cattle on their poor farm land,but before the cattle are sold, they are taken to greener lands in the south to get fat.
26. What is the article mainly concerned？
A.The problem of spreading desert.
B.The rainfall and vegetation in desert areas.
C.The water collection systems.
D.The difference between modern life and ancient life.
27. “one out of seven” refers to____.
A.more than a third of the lands' earth
B.the percentage of the earth's land that is desert-like
C.the number of people who live in dry regions
D.a day of a week
28. In paragraph 2,“they are taken to the greener lands in the south.”They refers to____.
A.the Sahel farm land
B.the farmers
C.the cattles
D.the trees
29. How many ideas for saving the land are described？
A.Five. B.Two. C.Four. D.Three.
30. Which of the following statements is true, according to the passage？
A.The earth's desert are slowly spreading.
B.One out of 10 people lives in dry regions.
C.Their life in the desert is threatened now by traditional problems.
D.New water wells can solve the problem in Africa's desert.
第7题
Hair Detectives
Scientists have found a way to use hair to figure out where a person is from and where that person has been. The finding could help solve crimes, among other useful applications.
Water is central to the new technique. Our bodies break water down into its parts: hydrogen(氢)and oxygen. Atoms (原子) of these two elements end up in our tissues and hair.
But not all water is the same. Hydrogen and oxygen atoms can vary in how much they weigh. Different forms of a single element are called isotopes(同位素). And depending on where you live, tap water contains unique proportions of the heavier and lighter isotopes of hydrogen and oxygen.
Might hair record these watery quirks(古怪举动；怪僻). That's what James R. Ehleringer, an environmental scientist at the University of Utah in Salt Lake City, wondered.
To find out, he and his colleagues collected hair from barbers and hair stylists(发型师)in 65 cities in 18 states across the United States. The researchers assumed that the hair they collected came from people who lived in the area.
Even though people drink a lot of bottled water these days, the scientists found that hair overwhelmingly(压倒性地) reflected the concentrations of hydrogen and oxygen isotopes in local tap water. That's probably because people usually cook their food in the local water. What's more, most of the other liquids people drink including milk and soft drinks contain large amounts of water that also come from sources within their region.
Scientists already knew how the composition of water varies throughout the country. Ehleringer and colleagues combined that information with their results to predict the composition of hair in people from different regions. One hair sample used in Ehleringer's study came from a man who had recently moved from Beijing, China, to Salt Lake City. As his hair grew, it reflected his change in location.
The new technique can't point to exactly where a person is from, because similar types of water appear in different regions that span a broad area. But authorities can now use the information to analyze hair samples from criminals or crime victims and narrow their search for clues(线索).
What does the writer say about tap water？ Which of the following is NOT correct？
A．Tap water reflects the concentrations of hydrogen and oxygen isotopes in different regions.
B．Tap water is a kind of soft drink in the United States.
C．Tap water contains unique proportions of isotopes of hydrogen and oxygen.
D．Tap water is used to cook food.
第8题
As an illustration of this we can consider the discovery of air pressure. Over two thousand years ago, men discovered a method of raising water from one level to another by means of the vacuum pump. When, however, this machine passed into general use in the fifteenth and sixteenth centuries, it was not possible to raise water vertically more than about 35 feet. Why？ Galileo, amongst others, recognized the problem, but failed to solve it.
The problem was then attacked by Torricelli. Analogizing(作类比推理) from the recently-discovered phenomenon of water-pressure, he postulated(假定) that a deep "sea of air" surrounded the earth; it was, he thought, the pressure of this sea of air that pushed on the surface' of the water and caused it to rise in the vacuum tube of a pump. A hypothesis, then, was formed. The next step was to deduce the consequences of the hypothesis. Torricelli reasoned that this "air pressure" would be unable to push a liquid heavier than water as high as 35 feet, and that a column of mercury(水银), for example, which weighed about 14 times more than water, would rise to only a fourteenth of the height of water, i.e. approximately 2.5 feet. He then tested this deduction by means of the experiment we all know, and found that the mercury column measured the height predicted. The experiment therefore supported the hypothesis. A further inference was drawn by Pascal, who reasoned that if this "sea of air" existed, its pressure at the bottom(i.e. sea level) would be greater than its pressure further up, and that therefore the height of the mercury column would decrease in proportion to the height above sea-level. He then carried the mercury tube to the top of a mountain and observed that the column fell steadily as the height increased, while another mercury column at the bottom of the mountain remained steady. This further proof not only established Torricelli's hypothesis more securely, but also demonstrated that, in some aspects, air behaved like water.
Why does the author mention the discovery of air pressure？
A．To show that air behaves like water in some aspects.
B．To illustrate the special sequence of procedures involved in the establishment of the working laws of science.
C．To indicate that it was difficult to use scientific methods to solve the problem of vacuum pump.
D．To show how scientists make experiments to test their deductions.
第9题
Part A
You are allowed 40 minutes to write a composition of about 150 words about Water Short age. Take the following points as reference:
1) the importance of water to man;
2) the increasing need for water;
3)the ways to solve the problem.
第10题
听力原文： Villages in developing countries often lack many things--books, clean water, electricity. These shortages are easy to see. But a different kind of shortage is not easy to see. That is a shortage of experts. Many villages have no doctors, engineers or scientists. They have no one who knows how to treat unusual medical problems or design a new expert system. There's a way to ease these problems. They can do it with computers. In the past few years, computer scientists around the world have developed what they call expert systems. An expert system is a special kind of computer program. In some situations, it can take the place of a human expert. For example, an expert in medical system can help care for a sick person. A question appears on the computer screen, "Is the person hot？" You tell the computer either yes or no. The computer asks other questions. "Has the person lost any blood？" "Can the person move normally？" You answer. The computer continues to ask questions until it has enough information to make a decision. Then it tells what medicine or other treatment is needed. In this way the expert system takes the place of a doctor. Another kind of expert system takes the place of an engineer. It measures the flow of water in a river. It tells if a dam can be built on the river. It also tells how much electricity can be produced. Still other kinds of expert systems help solve problems for farmers and owners of small businesses.
(23)
A．Lack of electricity.
B．Shortage of books.
C．Lack of clean water.
D．Shortage of experts.
