A
Trees are useful to man in three important ways：they give him wood and other useful things, they give him cool places, and they help to stop drought and flood.
Unluckily, in many parts of the world, man has not found that the third of these points is the most important.Man wants to make money from trees, so he has cut them down in large numbers, only to find that without them he has lost the best friends he had.And also, he is usually too careless to plant and look after new trees.So the forests slowly disappear.
This does not only mean that man will have fewer trees.The results are even worse：for where there are trees, their roots break up soil — make the rain in — and also bind the soil, thus stopping it from being washed away easily; but where there are no trees, the rain falls on hard ground and flows away, causing floods and carrying away the rich topsoil.When all the topsoil is gone, nothing is left but useless desert.
语篇解读：本文是一篇说明文。文章主要介绍了树对人类的作用非常大，可以给人类提供木材、提供阴凉，还可以帮助阻止干旱和洪水。但实际情况是很多人砍掉了很多树木，破坏了植被，引起了生态危机。
1．The most important points of trees to man is that ．
A．they help him to stop drought and flood
B．they help him to make money
C．they give him cool places
D．they give him wood and other things
解析：选A 细节理解题。根据第一段内容及第二段中的Unluckily, in many parts of the world, man has not found that the third of these points is the most important.可知树木的第三个用途stop drought and flood最重要，故A项正确。
2．In many places forests slowly disappear because ．
A．many trees have been cut down by man
B．new trees are not well looked after
C．man has not paid enough attention to planting trees
D．all the above
解析：选D 细节理解题。根据第二段中的Man wants to make money from trees, so he has cut them down in large numbers, only to find that without them he has lost the best friends he had.And also, he is usually too careless to plant and look after new trees.So the forests slowly disappear.可知A、B、C三项都是树林消失的原因。故D项正确。
3．Land becomes desert after all trees are cut down because ．
A．roots of trees break up the soil
B．there are too many rainfalls
C．strong winds bring a lot of sand
D．there are no longer trees to keep the rain and protect the topsoil.
解析：选D 细节理解题。根据第三段中的The results are even worse：for where there are trees, ... soil, thus stopping it from being washed away easily; but where there are no trees, the rain falls on hard ground and flows away, causing floods and carrying away the rich topsoil.When all the topsoil is gone, nothing is left but useless desert.可知，当树被砍掉以后，再也没有树来保护水土了，导致土地变成了荒漠。故D项正确。
4．Which title best fits the passage?
A．Trees and Man
B．The Function of Tree Wood
C．How do People do with Trees?
D．The Usage of Tree Roots
解析：选A 标题归纳题。本文介绍了树对人类的作用非常大，可以给人类提供木材、提供阴凉，还可以帮助阻止干旱和洪水。但实际情况是很多人砍掉了很多树木，破坏了植被，引起了生态危机。所以本文主要讲述的是树和人类的关系，A项作标题最能概括本文内容，故A项正确。
