Force other than damaging winds are also at work inside tornadoes. Sometimes, as the turning, jumping funnel(漏斗) passes over a house, the walls and ceiling burst apart as if a bomb had gone off inside. This explosion(爆炸) is caused by the low air pressure at the center of a tornado.

The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado funnel passes over a small building that measures 20 by 10 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57,600 pounds. The pressure on the four walls adds up to 172,800 pounds.

If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the great inside pressure may cause the building to burst.

　　Unfortunately, heavy rain happens in thunderstorms that later produce tornadoes. So, people often shut all windows to protect their property. This may cause far worse damage later.

63. Which of the following is the main topic of the passage?

A. Where tornadoes are formed. 　　      B. When tornadoes usually occur.

C. How tornadoes can be prevented.　　     D. Why tornadoes cause so much damage.

64. According to the passage, tornadoes can destroy building because the _____.

A. force of a tornado increases the air pressure in a building

B. air pressure at the center of a tornado is over 172,000 pounds

C. weight of a tornado can crush a building’s roof when it passes overhead

D. air pressure inside a tornado is less than the air pressure inside a building

65. According to the passage, the pressure on a building during a tornado can be reduced　　　　by _____.

A. closing the windows 　　　　　        B. opening the windows

C. using an electric fan 　　　　          D. making the roof and walls stronger

　　In 1961, scientist set up gigantic, sensitive instruments to collect radio waves from the far reaches of space, hoping to discover in them some mathematical pattern indicating that the waves were sent out by other intelligent beings. The first attempt failed, but someday the experiment may succeed.
　　What reason is there to think that we may actually detect intelligent life in outer space？To begin with, modern theories of the development of stars suggest that almost every star has some sort of family of planets. So any star like our own sun （and there are billions of such stars in the universe） is likely to have a planet situated at such a distance that it would receive about the same amount of radiation as the earth.
　　Furthermore, such a planet would probably have the same general composition as our planet; so, allowing a billion years or two or three, there would be a very good chance for life to develop, if current theories of the origin of life are correct.
　　But intelligent life？Life that has reached the stage of being able to send radio waves out into space in a deliberate pattern？Our own planet may have been in existence for five billion years and may have had life on it for two billion, but it is only in the last fifty years that intelligent life capable of sending radio waves into space has lived on earth. From this it might seem that even if there were no technical problems involved, the chance of receiving signals from any particular earth-type planet would be extremely small.
　　This does not mean that intelligent life at our level does not exist somewhere. There are such an unimaginable number of stars that, even at such miserable possibility, it seems certain that there are millions of intelligent life forms scattered through space. The only trouble is, none may be within easy distance of us. Perhaps none ever will be; perhaps the distances that separate us from our fellow “creatures” of this universe will forever remain too great to be conquered. And yet it is conceivable that someday we may come across one of them or, frighteningly, one of them may come across us. What would they be like, these outside-the-earth creatures？
1.What point is the author making by stating that almost every star has some sort of family of planets？
　　A. Sooner or later intelligent beings will be found on one of the stars.
　　B. There must be one or two of the planets on which there are no intelligent beings.
　　C. There are sufficient planets for there to be one that enjoys the same conditions as the earth does.
　　D. One or two billion years later intelligent beings will generate on those planets.
2.What is the main topic of the passage？
　　A. Some probable intelligent life forms on other planets.
　　B. Various stages undergone by the intelligent life on other planets.
　　C. Grounds for probable existence of intelligent life on other planets.
　　D. The possibility of intelligent life existing on our planet.
3.Which of the following can be inferred from the passage？
A. An encounter is probable between people from the earth and intelligent beings from another planet.
B. Though the first attempt failed, scientists did discover the radio waves sent out by other intelligent beings.
C. Other intelligent beings were able to send our radio waves into space well before the last fifty years.
D. It is certain that there are millions of intelligent beings scattered in space but only too far away.
4.According to the author, what is the difference between “we may come across one of them” and “one of them may come across us”？
A. The earth would be dangerously disadvantaged if it is sought after by possibly much more developed creatures.
B. It would prove that there are too many outside-the-earth creatures if “one of them comes across us”.
C. The history of the development of the earth would be proved to be shorter than that of “them” if “they” come across us.
D. it would prove that the distance in between is not so great as we think if “we come across one of them” someday.

阅读理解

　　This is the story of a small boy, who lived a long time ago in Germany . His name was George Frederick Handle .

　　As a very young boy, he loved music most. But his father didn't allow him to play any music.

　　Then one day he waited until he was all alone at home. Quickly he ran to his hiding place, he and a friend carried a small piano into the house. He decided to put it in his hiding place. There no one could see it.

　　That night, when everyone else wag asleep, he went to his hiding place. The moon was shining through a broken window. He sat on a box and began to play the piano. At that moment he knew he could only be happy playing music the rest of his life.

　　He played on and on, and he filled his house with his music. “George!” cried his father, “What are you doing? Stop that playing now! ”

　　The music stopped. George had tears in his eyes. Then he turned to his father and said, “Papa, you must understand I love music. It is my whole life.”

　　“Now listen to me, you foolish boy,” said Mr. Handle, “I want you to be a rich man. I want you to work hard. 1 don't want you to be a poor man all your life. You must leave music and become a doctor. Don't let me see you at the piano again.”

　　One day George found his way to church. He went straight to the organ(管风琴)and began to play it . He was only seven years old then. The story of his music spread in his town.

　　When the Duke heard the story, he said, “This boy must have the best music teacher. ” So George began to take music lessons.

　　George's teacher was very good. He taught George well and helped him write his own music. George became famous when he was eleven years old. Now his music is played all over the world.

1．Why didn't George listen to his father?

[　　]

A．He deeply loved music .

B．He didn't think his father was right.

C．He didn't want to go to school.

D．Music could make him rich.

2．What did George's father want him to be?

[　　]

A．A businessman.

B．A teacher.

C．A doctor.

D．A musician.

3．“Duke” is probably ________.

[　　]

A．a doctor

B．a nobleman

C．a good music teacher

D．a shop manager

4．The title “The Musical Heart” means ________.

[　　]

A．George began to play the piano when he was very young.

B．George played the piano pretty well .

C．George was a good music teacher.