Geologists have been studying volcanoes for a long time.Though they have learned a great deal,they still have not discovered the cause of volcanic action.They know that the inside of the earth is very 题目和参考答案——青夏教育精英家教网—

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Geologists have been studying volcanoes for a long time.Though they have learned a great deal,they still have not discovered the cause of volcanic action.They know that the inside of the earth is very hot,but they are not sure exactly what causes the great heat.Some geologists have thought that the heat is caused by the great pressure of the earth’s outer layers.Or the heat may be left from the time when the earth was formed.During the last sixty years scientists have learned about radium,uranium,thorium,and other radioactive elements.Many scientists now believe that much of the heat inside the earth is produced by radioactive elements.

Whatever the cause of the heat may be,we do know that the earth gets hotter the farther down we dig.In deep mines and oil wells the temperatures rise about 1°F for every 50 feet.At this rate of the temperature 40 miles below the earth’s surface should be over 4 000°.This is much hotter than necessary to melt rock.However,the pressure of the rock above keeps most materials from melting at their usual melting points.Geologists believe that the rock deep in the earth may be plastic,or puttylike（油灰状的）.In other words,the rock yields slowly to pressure but is not liquid.But if some change in the earth’s crust releases the pressure,the rock melts.Then the hot,liquid rock can move up toward the surface.

1.The cause for the great heat inside of the earth is______.

A.great pressure of the earth’s outer layers

B.the heat left from the time when the earth was formed

C.radioactive elements giving out heat

D.not sure

2.According to the passage,______ prevents most rock from melting at its usual melting points.

A.the pressure of the rock itself

B.the pressure of the rock above

C.the pressure of the earth’s outer layers

D.the heat given out by some radioactive elements

3.According to the passage,which of the following is NOT true?

A.The farther down,the hotter the earth gets.

B.The rock deep in the earth is liquid.

C.When the pressure releases from the earth’s crust,the rock melts.

D.Rock would be melted at 4 000°.

1.解析：作者在回答这个问题，用的都是“或许”“有些科学家”的字词，并没有把握。

答案：D

2.解析：“However，the pressure of the rock above keeps most materials from melting at their usual melting points.”一句给了我们答案。

答案：B

3.解析：“In other words，the rock yields slowly to pressure but is not liquid.”一句说明在地球里面的岩石并不是液体，只有地球释放了这种压力，它们才以液体的形式涌向地球表面。

答案：B

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I know that our geologists think highly of his researches in the ______

　　A. land　　B. field　　C. ground　　D. Place

Ladies and Gentlemen：

Welcomed to the West Lake. First of all, let me make a brief introduction for it .

The West Lake like a shining pearl lying in the west of Hangzhou City. Surrounded by hill on the three sides, it is famous for it beautiful scenery, a plenty of historic sites and a variety of local products. Legend has it that the West Lake was a jewel falling from heaven when geologists insist this place had been a shallow sea gulf before it became that it is today. In any case, the West Lake inspired poets and painters for centuries. Enjoy your trip. Thank you !

Situated in the Northeast region of Vietnam, Halong Bay is made up of 1,969 islands of various sizes, 989 of which have been given names. The concentrated zone of stone islands is famous for its spectacular scenery of caves, and forms the central zone of Halong Bay.

Seen from above, Halong Bay looks like a geographic work of art. While exploring the bay, you feel lost in a wonderful world. There is Man’s Head Island, which resembles a man standing and looking towards the mainland. Dragon Island looks like a dragon winding above the blue water. La Vong Island resembles an old man fishing. There are also the islands of the Sail, the Pair of Roosters, and the Incense Burner, which are all astonishingly like their names.

It has been proven by scientists that Halong Bay was one of the first places of human existence. It is also a region of highly-concentrated biological diversity with many ecosystems of coral reefs, and tropical forests, which are home to thousands of species of animals and rare plants.

The beach located along the coast of Halong Bay has a year-round average temperature of 20℃. Among the palm trees are large hotels. Visitors are seen on white sand and under the green trees are small family-run restaurants. After swimming, tourists can enjoy cold drinks. No wonder the 18h meeting of the Committee of the World Heritages of UNESCO officially recognized Halong Bay as a natural heritage site of worldwide importance.

1.What forms the central zone of Halong Bay?

A. 1,969 islands of various sizes.

B. The concentrated zone of stone islands.

C. 989 islands that have been given names.

D. Man’s Head Island.

2.We can infer that the names of most islands ______.

A. have something to do with theirs shapes.

B. were given by the visitors in Halong Bay

C. were given by the geologists of Vietnam

D. are related to their history

3. The author writes the passage mainly to_______.

A. tell some information about the history of Vietnam

B. introduce the average temperature in Vietnam

C. introduce the beach of Vietnam

D. tell readers something about Halong Bay

The ocean bottom，a region nearly 2.5 times greater than the total land area of the Earth， is even today largely unexplored. Until about a century ago，the deep-ocean floor was completely inaccessible and hidden beneath waters averaging over 3，600 meters deep. Totally without light and subjected to intense pressures hundreds of times greater than at the Earth's surface，the deep-ocean bottom is a strange environment to humans，in some ways as forbidding and remote as the outer space.

Although researchers have taken samples of deep-ocean rocks for over a century，the first detailed global study of the ocean bottom did not actually start until 1968，with the beginning of the National Science Foundation's Deep Sea Drilling Project ( DSDP). Using techniques first developed for the offshore oil and gas industry，the DSDP's drill ship，the Glomar Challenger，was able to maintain a steady position on the ocean's surface and drill in very deep waters，taking samples of rock from the ocean floor.

The Glomar Challenger completed 96 voyages in a 15-year-research program that ended in November 1983. During this time，it sailed 600，000 kilometers and took almost

20，000samples of rocks around the world. Those samples have allowed geologists to reconstruct what the planet looked like hundreds of millions of years ago and to make out what it will probably look like millions of years in the future. Today，largely on the strength of evidence gathered during the Glomar Challenger's voyages，nearly all earth scientists agree on the theories of plate tectonics (构造学) and continental drift that explains many of the geological processes.

The samples of rocks drilled by the Glomar Challenger have also provided a climatic record stretching back hundreds of millions of years. The information of past climatic changes can be used to predict future climates.

1.The underlined word" inaccessible" in Line 3 means .

A. unrecognizable B. unreachable C. unusable D. unreasonable

2.Why does the author mention "outer space" in the first paragraph?

A.The Earth's climate millions of years ago was similar to that in outer space.

B.It is similar to the ocean floor in being strange to the humans.

C.Rock formations in outer space are similar to those found on the ocean floor.

D.Techniques used by scientists to explore outer space were similar to those used in ocean exploration.

3.Which of the following is TRUE of the Glomar Challenger?

A. It is a type of submarine. B. It is an ongoing project.

C. It has gone on over 100 voyages. D. It made its first DSDP voyage in 1968.

4.The Deep Sea Drilling Project was significant because it was .

A.an attempt to find new sources of oil and gas

B.the first extensive exploration of the ocean bottom

C.made up of geologists from all over the world

D.supported entirely by the gas and oil industry

5.Which is NOT mentioned in the passage as being a result of the Deep Sea Drilling Project?

A.Geologists were able to determine the Earth's appearance millions of years ago.

B.Two geological theories became more widely accepted by scientists.

C.Geologists observed forms of life never before seen.

D.Information was revealed about the Earth's past climatic changes.

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