大学英语四级试练习卷一、阅读理解阅读理解（一）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 taller B.improve the shape of the tree C.get rid of the small branches D.make the small branches thicker2.Trees become unhealthy if the gardener _.A.allows too many branches to grow in the middle B.does not protect them from wind C.forces them to grow too quickly D.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 year B.as quickly as possible C.occasionally when necessary D.regular every winter5.What was the authors purpose when writing this ?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.阅读理解（二）Liberia, the oldest independent Negro state in West A frica, has been struggling for survial ever since its foundation in 182 2.Progress has been hampered by constant hostility between the American Negroes whose families returned there in the early 19th century, and the West Africans whose ancestors never left the continent. Though the two groups are of the same race, they are divided by language and outlook and regard each other with deep suspicion creating a conflict which was not foreseen by Liberias founders. In addition, neighboring states, native tribel,disease, and poverty have made life dangerous and difficult. The government has tried desperately,through loans and a trickle of trade, to make ends meet.Anxiety about financial matters lessened somewhat when,in 1910, the United States accepted responsibility for Liberias sruvival. However, not until Harvey Firestone, the American rubber king,decided that the United States must produce itsown rubber-with Liberia as the site of the rubber plantations-did liberia have much hope of paying its debts and balancing its budget. The rubber industry,founded in the 1920s ,and the activity that followed it brought both progerss and profit to LiberiA. Before that time Liberia had no roads, no mechanical transport and no good port; its people had little education and few tools. Liberians feel that the country is being ruled by rubber. For this reason, the recent discovery of iron ore is important. Liberian leaders are trying to moderate the power of the ruvver industry and to estaglish the countrys political and economic independence.1.Liberia has been in idffculty since its independence mainly because_.A.the american negroes do not want to help the country. B.there have been constant hostillity and suspicion between different tribes in the country. C.there haven been constant hostility and suspicion between two groups of the same tride. D.the goverment has adoped a wrong policy2.The government has tried desperately, through loans and a trickle of trade, to make ends meet. to make ends meet means_.A.the goverment has to borrow money from others B. the goverment has to lend money to others C.the goverment doesnt have to borrow or lend money D.the goverment has either to borrow or to lend money