71. If the bottom of an object is　　______　 its top, it will fall over easily.

　　A. lighter than　　　　 B. heavier than　　　 C. not lighter than 　D. as heavy as

70. "Home for the aged " means ___

A. a home which has old people

B. a home without children

C. a place that supplies care and service for the old　

D. a place where the old like to go

　　　　　　　　　　　　　　　　　 E

　 　 Every object has weight. But the center of its weight is not always in the middle of the object. If the top of an object is heavier than its bottom, it will fall over easily. We say that its center of gravity is high. But if the bottom is heavier, it won’t fall easily. Then we say that its center of gravity is low.

　　　 Look at the first picture. This empty box must fall over, because its center of gravity(C)is not above the line of its bottom(AB)

Now look at the second picture. There is some heavy iron in the bottom of this box. It will not fall, because its center of gravity is above its bottom.

69. The most important things that the "Big Brothers “ teach fatherless boys are ____.

A. fishing　　　　 B. playing ballgame

C. things usually learned from fathers　　 　　　 　

D. how to help and bring happiness to others

68. Clubs for boys and girls like to use high school or college students because ____.

A. they understand the boys and girls better　　　　 B. they are young and strong

C. they can play various games　 　　　　　　　　D. they are good at teaching

67. In this passage 'volunteers’ are people ____.

A. who are taken care of in hospitals　　　　　　

B. who offer free service to help others

C. who serve in orphanages 　 D. who organize clubs　　　　　　　　　　　

66. The idea of wheels may have come from ___.

A. running after an animal in order to kill it 　　　

B. rolling a dead animal on logs

C. watching running animals

D. watching a rolling stone

D

Every country has many good people who help to take care of others. Some　 high school　 students　 and college　 students　 in the United States often spend many　 hours as　 volunteers　 in a hospital , orphanage (孤儿院 ) or home for the aged . They read books to the people who are in these places, or they just visit them and play games or listen to their problems. Other young people volunteer to collect food or money, or they work in the homes of people who are sick or old. There are a group of volunteers to meet every need. For boys who no longer have fathers, there is an organization called Big Brothers. College students and other man take these boys to ball games or on fishing trips and help then to know about things that boys learn from their fathers.

Every city has a number of clubs where boys and girls can go to play games or to learn skills. Most of the clubs use high school and college students because they still remember the problems of younger boys and girls. An organization called Future Farmer of America will help young people living on farms to learn more about raising food and animals.

Volunteers believe that some of the happiest people in the world are those who help to bring happiness to others.

65. This passage says that the first wheel may have been a ___.

A. a round piece of stone 　　　 B. a piece of heavy log

C. a piece of metal　　　　　　 D. a tree

64. The wheel was probably invented by ___.

A. a group of early hunters　　　　　　

B. the first men on earth　

C. great prehistoric thinkers 　 　

D. the man who made the first cart

63. The new compute can Not ___.

A. help the students learn English 　　　

B. show sentences to the students

C. teach the students English 　　　　　　　

D. love the students and understand their thoughts.　

C

　　 Man's first real invention, and one of the most important inventions in history, was the wheel. All transportation and every machine in the world depend on(依靠) it.

The wheel is the simplest yet perhaps the most unusual of all inventions, because there are no wheels in nature. No living thing was ever born with wheels. How then, did man come to invent the wheel?

Perhaps some early hunters found that they could roll the dead body of a heavy animal through the forest on logs (圆木) more easily than they could carry it. However, the logs themselves weighed a lot.

It must have taken a great prehistoric(史前) thinker a long time to imagine two thin pieces log connected at their centers by a strong stick. This would roll along just as the logs did, yet be much lighter and easier to handle. Thus the wheel and axle (轴) came into being, and with them the first carts were made.

62. Among the following ideas, which do you think Harbor would agree to ?

A. The students can learn more from a computer than from a “person”

B. A human teachers is always important in teaching English

C. A computer can take the place of a human teacher.

D. Practising sentences in a computer will make students excited