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.

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

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

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°.

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°.

I have been very lucky to have won the Nobel Prize twice. It is, of course, very exciting to have such an important recognition of my work, but the real pleasure was in the work itself. Scientific research is like an exploration of a voyage of discovery. You are continually trying out new things that have not been done before. Many of them will lead nowhere and you have to try something different, but sometimes an experiment does work and tells you something new and that is really exciting. However small the new finding may be, it is great to think “ I am the only person who knows this” and then you will have the fun of thinking what this finding will lead to and deciding what will be the next experiment. One of the best things about scientific research is that you are always doing something different and it is never boring. There are good times when things go well and bad times when they don’t. Some people get discouraged at the difficult times but when I have a failure, my policy has always been not to worry but to start planning the next experiment, which is always fun.

   It is very exciting to make a new discovery. Some people will do the strangest things for this excitement, such as going round the world in a balloon or walking to the North Pole. There are not many new places to explore but there is a lot of new information to be discovered in science and a journey into this unknown area can be much more worthwhile and just as exciting.

   I am sometimes asked, “What do you have to do to win a Nobel Prize?” My answer is: “I don’t know. I have never tried.” But I know of one way not to win one. There are some people whose main reason for doing science is to win prizes and they are always thinking about how to do it. Such people don’t succeed. To do good science you must be interested in it and enjoy doing experiments and thinking out problems. And, of course, you must be prepared to work hard and not to be too discouraged by failure.

1.In the writer’s eyes his greatest pleasure in all his lifetime is _______.

A. to win the Nobel Prize for the first time

B. to be awarded the Nobel Prize for the second time.

C. in the work itself

D. to have a much more important recognition of his work.

2.Why did the writer think scientific research to be one of the best things?

A. You will be able to win the Nobel Prize through the scientific research

B. You can make as much money as possible by doing the scientific research.

C. You may continue doing with something different and exciting, so you can never be tired of doing the scientific research.

D. You can get much more chances of promotion by making the scientific research.

3.What would the writer do when he had a failure?

A. He would forget this failure and start the next experiment.

B. He used to be worried about it for several days and never forget it.

C. He always gave up his study as the result of the failure.

D. He used to think out the reasons and then continue to do it again.

4.Which of the following is true according to the passage?

A. The writer could still keep calm when he heard the news that he had won the Nobel Prize.

B. The writer always gave up his courage when he met with some difficulties in the course of his scientific research.

C. In the field of science there are still many new things which need to be studied further.

D. There are still many exciting places to explore in the world.

Geologists have been studying volcanoes(火山)for a long time. Though they have learned a great deal, they still have not discovered the causes 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. These give out heat all the time as they change into other elements. Many scientists now believe that much of the heat inside the earth is produced by radioactive elements.

Whatever the cause of the heat might be, we do know that the earth gets hotter the farther down we dig. In deep mines and oil wells the temperature rises about 1 degree F for each 50 feet. At this rate the temperature 40 miles below the earth's surface would be over 4,000 degrees F. 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. In other words, the rock yields(屈服)slowly to pressure but is not liquid. But if some change in the earth's outer layer releases the pressure, the rock melts. Then the hot, liquid rock can move up toward the surface.

4. The subject of this passage is the________.

A. formation of volcanoes

B. results of volcanic action

C. heart of the earth

D. causes of the earth's inside heat

5. The cause for the heat in the interior of the earth is probably________.

A. radioactive elements

B. the great pressure of the earth

C. not determined

D. the heat remaining from the formation of the earth

6. If the temperature at the earth's surface is 20°F, the temperature in a coal mine 500 feet below the surface would, in degree, be________.

A. 40 B. 30 C. 50 D. 120

7. Why doesn't the rock deep in the earth melt as a liquid at such high temperature?

A. Because the temperature isn't high enough to melt it.

B. Because it may be plastic.

C. Because the pressure of the rock above is strong enough to stop it melting.

D. Because there isn't oxygen inside the earth.

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. 1.

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

   1. A.
      great pressure of the earth’s outer layers
   2. B.
      the heat left from the time when the earth was formed
   3. C.
      radioactive elements giving out heat
   4. D.
      not sure
2. 2.

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

   1. A.
      the pressure of the rock itself
   2. B.
      the pressure of the rock above
   3. C.
      the pressure of the earth’s outer layers
   4. D.
      the heat given out by some radioactive elements
3. 3.

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

   1. A.
      The farther down,the hotter the earth gets.
   2. B.
      The rock deep in the earth is liquid.
   3. C.
      When the pressure releases from the earth’s crust,the rock melts.
   4. D.
      Rock would be melted at 4 000°.