Passage Two

　　Questions 26 to 30 are based on the following passage.

　　Trees are useful to man in three very important ways: they provide him with wood and other products; they give him shade; and they help prevent drought (干旱) and floods.

　　Unfortunately, in many parts of the world, man has not realized that the third of these services is the most important. In his eagerness to draw quick profit from the trees, he has cut them down in large numbers, only to find that with the trees used he has lost the best friends he had. Two thousand years ago a rich and powerful country cut down its trees to build warships with which to gain itself an empire. It gained the empire but without its trees, its soil became hard and poor. When the empire fell to pieces, the home country found itself faced with floods and starvation.

　　Even where a government realizes the importance of a rich supply of trees, it is difficult for it to persuade the villager to see this. The villager wants wood to cook his food with: and he can earn money by making charcoal(木炭) or selling wood to the townsman(城里人).He is usually too lazy or too careless to plant and look after new trees. So, unless the government has a good system of control, or can educate the people, the forests will slowly disappear.

　　This does not only mean that the villagers’ sons and grandsons have fewer trees. The results are even more serious. For where there are trees, their roots break up the soil allowing the rain to sink in and also bind the soil, thus preventing the soil from being washed away easily. But where there are no trees, the rain falls on hard ground and flows away on the surface, causing floods and carrying away with it the top-soil, in which crops grow so well. When all the top-soil is gone, nothing remains but worthless desert.

　　26. It is most important for man to realize that trees _______.

　　A. provide him with wood

　　B. help prevent drought and floods

　　C. give him shade

　　D. help him get quick profit

　　27. By the story of the empire, the writer tries to tell us people _______.

　　A. are often eager to get quick profit from trees

　　B. will suffer by cutting down their trees

　　C. can make their country rich and powerful with trees

　　D. will not make an empire without trees

　　28. The government should help the villager realize the importance of trees by _______.

　　A. suggestion B. money C. education D. force

　　29. The most serious problem is that we don’t ______.

　　A. work hard to plant more trees

　　B. take good care of new trees

　　C. know the real importance of trees

　　D. leave more trees for our sons and grandsons

　　30. In the last paragraph, the writer emphasizes his point by means of _______.

　　A. contrast B. example C. criticism D. definition