Trees should only be prunedwhen there is a good and clear reason fordoing so and, fortunately, the number of such reasons is small．Pruning involves the cutting away of overgrown and unwanted branches 题目和参考答案——青夏教育精英家教网—

题目内容

Trees should only be pruned（修剪）when there is a good and clear reason fordoing 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 cur 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 would is left on the tree and this provides an easy entry for diseases, but it is a wound that will heal（愈合）．Often there is a race between the healing and the disease as to whether the tree will live or die, or that there is a period when the tree is at risk．It should be the aim of every gardener to reduce the risk as far as possible．It is essential to make the area 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 the interference（妨碍）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.

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 branches. D．To make the small branches thicker.

2．Trees become unhealthy if the gardener .

A．helps a wound to dry.

B．covers a rough surface.

C．damages some of the small side branches

D．allows too many branches to grow in the middle

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 writing this passage?

A．To discuss different methods of pruning.

B．To introduce some common knowledge of pruning.

C．To explain how trees develop disease.

D．To give practical instruction for pruning a tree.

BDDCB

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The diagram is mainly about ______.

A．the food chain of the animal B．the system of energy flowing

C．how to get food for man D．the growth of the energy

Which is not the result of photosynthesis of the plant?

A．Oxygen is released into the air. B．Food is provided for animals.

C．Certain forms of energy is produced． D． The air is cleaned．

What occurs when the energy flows through the system?

A．Energy is consumed and one becomes the food of others.

B．Energy is stored and plants become animals.

C．Man plays an important part in energy flowing.

D．The more energy is consumed, the more energy the sun will supply.

What should be done in order to improve the living conditions according to the diagram?

A．More animals should be raised． B．Decomposers should be made full use of.

C．More trees should be planted． D．Man should be controlled．

(2011年潍坊质量监测)When people cut down big trees，new trees should be planted.________they will have no trees to cut down in the future.

A．If not B．If so

C．If no so D．If don’t

C
LONDON: What could possibly be wrong with planting trees? The benefits are obvious; they firm the soil, soak up (摄取) extra water and take carbon dioxide (二氧化碳) our of the atmosphere.
However, it now turns out that planting trees could add to global warming.
Tree roots do a great job of keeping soil firmly on the ground and out of the wind’s power. The problem is that some of those dust clouds play an important part in soaking up carbon dioxide.
Huge dust storms blow out over the oceans from dry parts of North Africa and central Asia. Tons of dust are lifted and left as a thin film over the ocean surface. The dust fuels oceanic life.
Dust from China is carried east and left in the Pacific Ocean. If a tree-planting programme there is successful and the dust supply reduced, the net result may be that less carbon dioxide gets locked away in the ocean.
Andy Ridgwell, an environmental scientist from the University of East Anglia, has spent the past few years studying dust and says his work “shows clearly that the complexity of the system and the importance of not tinkering(粗劣地修补) with it without understanding the results. For this reason the need is to focus(集中) on cutting carbon dioxide giving off rather than monkeying (瞎弄) about with the land surface.”
An American scientist, Robert Jackson, has shown that when native grassland areas are invaded(侵入) by trees, carbon is lost from the soil. “We are studying why the soil carbon disappears, but one theory is that trees do a lot more of their growing above ground compared to grasses, so less carbon goes directly into the soil from trees, ” says Jackson.
In wet areas of the world, the gain from trees absorbing carbon dioxide above ground seems to be outweighed(超过) by the loss of carbon from the soil below ground. Countries that plan to combat global warming by planting trees may have to think again.
Solutions to environmental problems are often more complex than they first appear, and understanding the Earth’s climate is a very great challenge.
63．People usually hold the opinion that       .
A．huge dust storms can destroy carbon dioxide
B．huge dust storms can destroy the oceans on the earth
C．huge dust storms can’t do anything beneficial for man
D．planting trees is the only way to control huge dust storms
64．Andy Ridgwell, the environmental scientist, believes that       .
A．dust plays a more important part than trees
B．trees should’t have been planted in dry places
C．carbon dioxide is harmful to everything on the earth
D．environmental problems are more complex than expected
65．Robert Jackson’s experiment proves that         .
A．grassland areas should be covered by forests
B．trees hold more carbon than grasses
C．carbon can turn grass into dust
D．less carbon can make trees grow faster
66．The underlined word “combat” in the last paragraph means      .
A．learn about      B．fight against     C．live with   D．give up

Trees should only be pruned (修剪) when there is a good and clear reason for doing so and , he 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 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 cause wounds . The health of a tree may be encouraged by removing branches that are blocking up the center 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 (愈合) . 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 important to make the area , which has been pruned , smooth and clan , 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 materials 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 (妨碍) from the leaves and also it is very unlikely that the cuts you make will bleed . If this does happen , it is , of course , impossible to paint them properly .

71．Why should running 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 .

72．Trees become unhealthy if the gardener .

A．To help a wound to dry .

B．To cover a rough surface .

C．damages some of the small side branches

D．Allows too many branches to grow in the middle

73．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 .

74．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

75．What was the author’s purpose when writing this passage ?

A．To discuss different methods of pruning .

B．To introduce some common knowledge of pruning .

C．To explain how trees develop disease .

D．To give practical instruction for pruning a tree .

Trees should only be pruned (修剪) when there is a good and clear reason for doing so and , 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 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 cause wounds. The health of a tree may be encouraged by removing branches that are blocking up the center 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 (愈合). 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 important to make the area, 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 materials 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 (妨碍) from the leaves and also it is very unlikely that the cuts you 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 a definite height

B. removing small side branches and making a tree look less thick

C. allowing too many branches to grow in the middle

D. having a tree surrounded by many other trees

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 writing this passage?

A．To discuss different methods of pruning.

B．To introduce some common knowledge of pruning.

C．To explain how trees develop disease.

D．To give practical instruction for pruning a tree.

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