There are many problems connected with space travel. The first and greatest of them is gravity (地球引力). If you let your pencil drop to the floor, you can see gravity in action. Everything is down to the earth by magnetic force. The weight of something is another way of describing the amount of force exerted on it by gravity. A rocket must go at least 2, 500 miles an hour to take anyone beyond the gravity of the earth into space.

Another problem is the strain that a person is subjected to when a rocket leaves the ground. Anything that is not moving tends to resist movement. As the rocket leaves the ground, it pushes upward, and the person is pushed back against the chair. During this thrust, gravity exerts a force on the body equal to nine times its normal force.

Once out of the earth's gravity an astronaut is affected by still another problem—weightlessness. Here, if a pencil drops, it doesn't fall. If a glass of water is turned upside down, the water will not fall out. All of us who are used to gravity expect things to have weightless conditions. Recent long flights have shown that the body needs special exercise in a spaceship.

　　  l. As a rocket leaves the ground, an astronaut experiences a force called——.

　　　　 A. gravity　　　　　　　　   B. a push

  　　   C. downward force　　　　    D. strain

　　 2. The force of gravity an astronaut is subjected to when the rocket leaves the ground is equal to

　　　　 A. 7 times its downward force　　　　　　  B. 5 times its normal force

　　　　 C. 3 times its upward force　　　　　　　　 D. 9 times its normal force

　　 3. Which of the following is not true according to the passage?

　　　　 A. Everything is down to the earth by magnetic force.

　　　　 B. Recent long flights have shown that the body needs special exercise in spaceship.

　　　　 C. A rocket must go at most 2, 500 miles an hour to take anyone beyond the gravity of the earth into space.

　　　　 D. There are many problems connected with space travel.

　　 4. Which is the best title for this passage?

　　　　 A. Weightlessness. Gravity and Strain Are All too Difficult to Understand

　　　　 B. Gravity is the Enemy of Space Travel

　　　　 C. Space Travel Problems

　　　　 D. People Cannot Leave the Earth Because of the Air

Another problem is the strain that a person is subjected to when a rocket leaves the ground. Anything that is not moving tends to resist movement. As the rocket leaves the ground, it pushes upward, and the person is pushed back against the chair. During this thrust, gravity exerts a force on the body equal to nine times its normal force.

Once out of the earth's gravity an astronaut is affected by still another problem—weightlessness. Here, if a pencil drops, it doesn't fall. If a glass of water is turned upside down, the water will not fall out. All of us who are used to gravity expect things to have weightless conditions. Recent long flights have shown that the body needs special exercise in a spaceship.

　　  l. As a rocket leaves the ground, an astronaut experiences a force called——.

　　　　 A. gravity　　　　　　　　   B. a push

  　　   C. downward force　　　　    D. strain

　　 2. The force of gravity an astronaut is subjected to when the rocket leaves the ground is equal to

　　　　 A. 7 times its downward force　　　　　　  B. 5 times its normal force

　　　　 C. 3 times its upward force　　　　　　　　 D. 9 times its normal force

　　 3. Which of the following is not true according to the passage?

　　　　 A. Everything is down to the earth by magnetic force.

　　　　 B. Recent long flights have shown that the body needs special exercise in spaceship.

　　　　 C. A rocket must go at most 2, 500 miles an hour to take anyone beyond the gravity of the earth into space.

　　　　 D. There are many problems connected with space travel.

　　 4. Which is the best title for this passage?

　　　　 A. Weightlessness. Gravity and Strain Are All too Difficult to Understand

　　　　 B. Gravity is the Enemy of Space Travel

　　　　 C. Space Travel Problems

　　　　 D. People Cannot Leave the Earth Because of the Air

With a good shopping position and the right amount（数量）of money , any educated person ought to be able to make a living out of a bookshop . It is not a difficult trade to learn and the large chain-stores can never force the small bookseller out of existence as they have done to the corner shop . But the hours of work are very long-I was only doing a part-time job , but my boss put in a seventy-hour week ,besides regular journeys out of shopping hours to buy books .

　　　 The real reason why I should not like to be back in the book trade for life , however , is that while I was in it, I lost my love of books . A bookseller cannot always tell the truth about his books , and that gives him a dislike for them . There was a time when I really did love books—loved the sight and smell and feel of them—if they were fifty or more years old , that is . Nothing pleased me quite so much as to buy a bargain lot of them on sale for several pounds . There is a peculiar flavour（独特的味道）about the unexpected books you pick up in that kind of collection: little-known eighteenth-century poets , or out-of-date geography books . For occasional reading—in your bath , for example , or late at night when you are too tired to go to bed—there is nothing as good as a very old picture story-book .

　　　 But as soon as I went to work in the bookshop, I stopped buying books . Seen in a mass, five or ten thousand at a time , books were dull and even a little tiresome . Nowadays I do buy one occasionally , but only if it is a book that I want to read and can’t borrow , and I never buy rubbish .

64. According to the passage , 　　 is one of the necessary conditions to run a bookshop .

　　　 A. an educated shop-owner　　

　　　 B. a good position at a street corner

　　　 C. a regular journey out of the shop　　

　　　 D. the force of large chain-stores

65. The author should not like to be back as a bookseller for life because 　　 .

　　　 A. he hated his job of selling books　　　

　　　 B. selling books was only a part-time job

　　　 C. the books in the shop gave him a dislike

　　　 D. he was unable to be honest about the books he sold

66. The books preferred by the author should be those 　　 .

　　　 A. stories making readers sleepless　　　　　

　　　 B. valuable ones bought on sale

　　　 C. peculiar ones with great expectation　　　　

　　　 D. geography ones from the eighteenth century

67. The author will only buy new books 　　 .

　　　 A. if he feels dull and tired　　　　　　　

　　　 B. after he gives up his job as a bookseller

　　　 C. which are interesting but hard to borrow

　　　 D. when he throws away old ones

Even if you are a good high-jumper, you can jump only about seven feet off the ground. You cannot jump any higher because the earth pulls you hard. The pull of the earth is called gravity.

　 You can easily find out the pull of the earth. If you weigh yourself, you will know how much gravity is pulling you.

　 Since there is gravity, water runs down hill. When you throw a ball into the air, it falls back down. Because of gravity, you do not fall off the earth as it whirls (旋转) around.

　 Then, can we get away from the earth and go far out into space? Now you can do it, because spaceships have been invented. Then spaceship will go so fast that it can escape (逃出) the earth’s gravity and carry you into space.

1. In this passage, the word “gravity” means_______.

　 A. the pull of everything.　　　　　 B. the force of attraction(吸引) among objects.

　 C. the force which attracts objects towards the centre of the earth

　 D. the force which attracts the earth towards the sun.

2. When you slip(滑) you always fall to the ground because________

　 A. the earth always turns round.　　　　　　　　　 B. the earth has gravity

　 C. the earth’s gravity is greater than your weight.　　 D. you are careless.

3. Gravity is strong that_______

　 A. it can throw a ball into the air.　　　　　 B. it makes you jump only seven feet.

　 C. it can let you fly away from the earth.　　 D. it can keep everything on earth.

4. Because of gravity,________

　 A. water flows everything.　　　　　 B. we can go everywhere by ship.

　 C. water always flows downwards.　　 D. fish can live in water.

5. We can get away from the earth by spaceship because________

　 A. the spaceship goes very fast.　　　 B. the earth can’t pull the spaceship.

C. the spaceship has a strong force.　 D. the spaceship can jump higher than others.

Habits, whether good or bad, are gradually formed. When a person does a certain thing again, he is driven by some unseen force to do the same thing repeatedly, then a habit is formed. Once a habit is formed, it is difficult, and sometimes impossible, to get rid of. It is therefore very important that we should pay great attention to the formation of habits. Children often form bad habits, some of which remain with them as long as they live. Older persons also form bad habits lasting as long as they live, and sometimes become ruined by them.　　
There are other habits which, when formed in early life, are of great help. Many successful men say that much of their success has something to do with certain habits in early life, such as early rising, honesty and so on.
　　Among the habits which children should not form are laziness, lying, stealing and so on. These are all easily formed habits. Unfortunately older persons often form habits which could have been avoided(避免).
　　We should keep away from(远离) all these bad habits, and try to form such habits as will be good for ourselves and others.
【小题1】________ are formed little by little.