2．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 （干旱） 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（根）break up soil-make the rain in-and also bind （固定） 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 top-sil．When all the top-soil is gone，nothing is left but
useless desert．
54．The most important points of trees to man is thatC．
A．they help him to make money
B．they give him cool
C．they help him to stop drought and floods
D．they give him wood and other things
55．In many places forests slowly disappear becauseD．
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
56．Land becomes desert（荒地）after all trees are cut down becauseD．
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 top-soil
57．Which title best fits the passage？A
A．Trees and Man
B．The Function of Tree Wood
C．How do People do with Trees？
D．The Usage of Tree Roots．
分析 本文是一片说明文．本文讲述了人和森林的关系．森林对于人类有很重要的意义，但最重要的是森林能够阻止洪涝和干旱．人们为了挣钱，会砍伐树木去卖钱．但是却很不认真的种新的树木，所以树木越来越少，干旱和洪涝频发，最终会变成沙漠．
解答 答案：CDDA．
54：C．细节理解题．根据Trees are useful to man in three important ways…they help to stop drought and flood．man has not found that the third of these points is the most important．树在三个方面对人类有帮助，第三点是帮助阻止干旱和洪涝，人类现在还没有发现其实第三点是最重要的，故C选项正确．
55：D．细节理解题．根据 so he has cut them down in large numbers人类砍了很多树 he is usually too careless to plant and look after new trees．So the forests slowly disappear．但是总是太不认真种，也不认真照顾新的树．所以森林慢慢减少．故D 选项正确．
56：D．细节理解题．根据where there are no trees，the rain falls on hard ground and flows away，causing floods and carrying away the rich top-soil．When all the top-soil is gone，nothing is left but useless desert．当没有树的时候，下的雨就把土地冲走，引起洪涝，带走肥沃的土壤．可以知道，当所有的顶部沃土都被冲走时，除了沙漠什么都没有留下，故D 选项正确．
57：A．标题归纳题．根据整篇文章，都是讲述人和树木的关系，故A 选项正确．
点评 阅读理解考查对文章的理解能力，在阅读全文的基础上，找出选项在文中对应位置，细节理解题应注意精确准确，不能以偏概全．
