大学英语四级阅读理解试题及答案（四）十六 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.Pruning should be done to _.a.make the tree grow tallerb.improve the shape of the treec.get rid of the small branchesd.make the small branches thicker2.Trees become unhealthy if the gardener _.a.allows too many branches to grow in the middleb.does not protect them from windc.forces them to grow too quicklyd.damages some of the small side branches3.Why is a special substance painted on the tree?a.To make a wound smoothb.To prevent disease entering a woundc.To cover a rough surfaced.To help a wound to dry4.A good gardener prunes a tree_.a.at intervals throughout the yearb.as quickly as possiblec.occasionally when necessaryd.regular every winter5.What was the authors purpose when writing this passage?a.To give pratical instruction for pruning a tree.b.To give a general description of pruningc.To explain how trees develop diseasesd.To discuss different methods of pruning.答案：babca十七 On Thursday afternoon Mrs. Carke, dressed for going out, took her handbag with her money and her key in it, pulled the door behind her to lock it and went to the over 60s Club. She always went there on Thursdays. It was a nice outing for an old woman who lived alone.At six oclock she cane home, let herself in and at once smelt cigarette smoke. Cigarette smoke in her house? How? How? Had someone got in? She checked the back door and the windows. All were locked or fastened, as usual. There was no sign of forced entry.Over a cup of tea she wondered whether someone might have a key that fitted her front door-a master keyperhaps. So she stayed at home the following Thursday. Nothing happened. Was anyone watching her movements? On the Thursday after that she went out at her usual time,dressed as usual, but she didnt go to the club. Instead she took a short cut home again, letting herself in through her garden and the back door. She settled down to wait.It was just after four oclock when the front door bell rang.Mrs. Clarke was making a cup of tea at the time. The bell rang again, and then she heard her letter-box being pushed open. With the kettle of boiling water in her hand, she moved quietly towards the front door. A long piece of wire appeared through the letter-box, and then a hand. The wire turned and caught around the knob on the door-lock. Mrs. Clarke raised the kettle and poured the water over the hand. There was a shout outside, and the skin seemed to drop off the fingers like a glove. The wire fell to the floor, the hand was pulled back, and Mrs. Clarke heard the sound of running feet.1.Mrs. Clarke looded forward to Thursday because_.a.she worked at a club on the dayb.she said visitors on Thursdaysc.she visited a club on Thursdayd.a special visitor came on Thursday2.If someone had made a forced entery,_.a.Mrs.Clarke would have found a broken door or windowb.he or she was still in the housec.things would have been thown aboutd.he or she would have needed a master key3.On the third Thursday Mrs. Clarke went out_.a.because she didnt want to miss the club againb.to see if the thief was hnging about outside