Trees should only be pruned when there is a good and clear reason for doing so and , fortunately,the number of such reasons is small. Pruning involves the cutting away of obergrown and unwanted branches, and the inexperienced gardener can be encouraged by the thought that more damage results from doing it unnecessarily than from leaving the tree to grow in its own way.

　　First, pruning may be done to make sure that trees have a desired shape or size. The object may be to get a tree of the right height, and at the same time to help the growth of small side branches which will thicken its appearance or give it a special shape. Secondly, pruning may be done to make the tree healthier. You may cut diseaed or dead wood, or branches that are rubbing against each other and thus cause wounds. The health of a tree may be encouraged by removing branches that are blocking up the centre and so preventing the free movement of air.

　　One result of pruning is that an open wound is left on the tree and this provides an easy entry for disease, but itis a wound that will heal. Often there is a race between the healing and the desease as to whether the tree will live or die, so that there is a period when the tree is at risk. It should be the aim of every gardener to reduce which has been pruned smooth and clean, for healing will be slowed down by roughness. You should allow the cut surface to dry for a few hurs and then paint it with one of the substances available from garden shops produced especially for this purpose. Pruning is usually without interference from the leaves and also it is very unlikely that the cuts yu make will bleed. If this does happen,it is, of course,impossible to paint them properly.

　　1.．Why should pruning be done?

　　A．To make the tree grow taller. B．To improve the shape of the tree.

　　C．to get rid of the small ranches . D．To make the small branches thicker.

　　2.．Trees become unhealthy if the gardener__________.

　　A. giving a tree a special shape and adefinite height

　　B. removing small side branches and making atree look less thick

　　C. allowing too many branches to grow in themiddle

　　D. having a tree surrounded by many othertrees

　　3.．Why is a special material painted on the tree?

　　A．To help a wound to dry. B．to cover a rough surface.

　　C．To make a wound smooth. D．To prevent disease entering a wound.

　　4.．A good gardener prunes a tree _________ .

　　A．several times throughout the year B．as quickly as possible

　　C．occasionally when necessary D．regularly every winter

　　5.．What was the author’s purpose when writingthis passage?

　　A．To discuss different methods of pruning.

　　B．To introduce some common knowledge of pruning.

　　C．To explain how trees developdisease.

　　D．To give practical instruction for pruning atree.

　　Baekeland and Hartmann report that the “short sleepers” had been more or less average in their sleep needs until the men were in their teens. But at about age 15 or so, the men voluntarily began cutting down their nightly sleep time because of pressures from school, work, and other activities. These men tended to view their nightly periods of unconsciousness as bothersome interruptions in their daily routines. In general, these “short sleeps” appeared ambitious, active, energetic, cheerful, conformist(不动摇) in their opinions, and very sure about their career choices. They often held several jobs at once, or workers full-or part-time while going to school. And many of them had a strong urge to appear “normal” or “acceptable” to their friends and associates. When asked to recall their dreams, the “short sleepers” did poorly. More than this, they seemed to prefer not remembering. In similar fashion, their usual way of dealing with psychological problems was to deny that the problem existed, and then to keep busy in the hope that the trouble would go away. The sleep patterns of the “short sleepers” were similar to, but less extreme than, sleep patterns shown by many mental patients categorized as manic(疯人). The “long sleepers” were quite different indeed. Baekeland and Hartmann report that these young men had been lengthy sleeps since childhood. They seemed to enjoy their sleep, protected it, and were quite concerned when they were occasionally deprived of their desired 9 hours of nightly bed rest. They tended to recall their dreams much better than did the “short sleepers.” Many of the “long sleepers” were shy, anxious, introverted (内向), inhibited (压抑), passive, mildly depressed, and unsure of themselves (particularly in social situations). Several openly states that sleep was an escape from their daily problems.

　　1. According to the report,______. A) many short sleepers need less sleep by nature B) many short sleepers are obliged to reduce their nightly sleep time because they are busy with their work C) long sleepers sleep a longer period of time during the day D) many long sleepers preserve their sleeping habit formed during their childhood

　　2. Many “short sleepers” are likely to hold the view that _____. A) sleep is a withdrawal from the reality B) sleep interferes with their sound judgement C) sleep is the least expensive item on their routine program D) sleep is the best way to deal with psychological troubles

　　3. It is stated in the third paragraph that short sleepers _____. A) are ideally vigorous even under the pressures of life B) often neglect the consequences of inadequate sleep C) do not know how to relax properly D) are more unlikely to run into mental problems

　　4. When sometimes they cannot enjoy adequate sleep, the long sleepers might ____. A) appear disturbed B) become energetic C) feel dissatisfied D) be extremely depressed