[单项选择]

B
Trees should only be pruned (修剪) when there is a good and clear reason for doing so and, fortunately, the number of such reasons is small. Pruning involves 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 trees to grow in their own ways.
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 the branches that are locking up the centre and so preventing the free movement of ai
A. Because it can help a wound to dry.
B. Because it can cover a rough surface.
C. Because it can make a wound smooth.
D. Because it can prevent disease entering a wound.

[单项选择]
Trees should only be pruned (修剪) when there is a good and clear reason for doing so and, fortunately, the number of such reasons is small. Pruning involves 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 trees to grow in their own ways.
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 the branches that are locking up the centre and so preventing the free movement of air.<
A. Because it can make trees grow taller.
B. Because it can improve the shape of the trees.
C. Because it can get rid of the small ranches.
D. Because it can make the small branches thicker.

[单项选择]Trees should only be pruned (修剪) when there is a good and clear reason for doing so and, fortunately, the number of such reasons is small. Pruning involves 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 trees to grow in their own ways.
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 the branches that are locking up the centre and so preventing the free movement of air.
One result of pruning is that an open wound i
A. Because it can make trees grow taller.
B. Because it can improve the shape of the trees.
C. Because it can get rid of the small ranches.
D. Because it can make the small branches thicker.