Trees should only be pruned (修剪, 整枝) when there is a good and clear reason for doing so and, fortunately, the number of such rea

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问题     Trees should only be pruned (修剪, 整枝) 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 overgrown 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 out diseased or dead wood, or branches that are rubbing against each other and thus causing 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 it is a wound that will heal. Often there is a race between the healing and the disease 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 that risk of death as far as possible. It is essential to make the wound on the tree 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 hours and then paint it with one of the substances available from garden shops produced especially for this purpose. Pruning is usually done in winter, for then you can see the shape of the tree clearly without interference from the leaves and it is. too very unlikely that the cuts you make will bleed. If this does happen, it is, of course, impossible to paint them properly.
Why is a special substance painted on the tree?

选项 A、To help a wound to dry.
B、To cover a rough surface.
C、To prevent disease entering a wound.
D、To make a wound smooth.

答案C

解析 本题问为什么要给树木涂上一种特殊的物质。本题是一道具体细节题。利用查阅式阅读法,我们可以在文章的最后一段中找到相关信息。这部分指出,剪枝的后果之一是给树留下创伤,这样就给疾病的侵入提供了便利,但是这种伤口可以愈合,通常愈合和发病的机会竞相存在,这关系到树的生与死,所以,这就使树面临一段时间的威胁。尽可能减少树木死亡的危险性应是每个园丁的目的所在。必须要使被修剪的树切口平整干净,因为剪切粗糙会减缓切口的愈合。应让切口表面干燥几小时,然后,去园艺用品店买些特殊涂料,涂在切口处。因此,我们可以推断出本题的正确答案应是C“这种特殊涂料可以防止疾病进入伤口”。
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