Plants are helpful to human: they provide us with wood and other products, they give us shade, and they help to prevent drought and floods.

    Sadly, 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 without them he has lost the best friends he had.

    Several 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 country found itself faced by floods and starvation.

    Even if a government realizes the importance of a plentiful 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. He is usually too lazy or too careless to plant and look after 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 the soil up—allowing the rain to sink in and also hold the soil, thus preventing it being washed away easily, but where there are no trees, the soil becomes hard and poor. The rain falls on hard ground and flows away on the surface, causing floods and carrying away with it the rich topsoil, in which crops grow so well. When all the topsoil is gone, nothing remains but a worthless desert.

材料一  开宝四年(971年)，宋太祖赵匡胤“置市舶司于广州，后又于杭、明州置司”……根据考古，东起日本，南到印尼，西到东非，甚至在非洲内陆的津巴布韦都有宋代瓷器的发现。……与宋代进行通商的国家和地区有50个，其中宋代海舶直接到达的有20多个(当时)。……北宋初年，广州的市舶收入只是占了国家财政收入的2%，到了南宋初年占据了全国财政收入的20%……

                                     ——摘编自梁俏《宋代海外贸易特点及其评价》

材料二 　明朝初年，曾与朱元璋争夺政权的张士诚、方国珍之余部，入海为盗，且“每诱岛倭(指日本倭寇)入掠”。《皇明祖训》记载，朱元璋认为，日本、安南(今越南)、暹罗(今泰国)等15国，“限山隔水，僻在一隅，得其地不足以供给，得其民不足以使令”，朝廷“禁滨海民不得私出海”“禁海民私通海外诸国”。

                                     ——摘编自李金明《明代海外贸易史》

材料三 　租界内康庄如砥，车驰，房屋多西式，轩敞华丽，有高至六七层者，钟楼矗立，烟突如林，入夜则灯火辉煌，明如白昼。……中西邮局、海关、银行、领事馆、电报局、巡捕房、丝厂、船坞、轮船公司皆在焉。……沪地教堂林立，规模宏大……

                                                  ——李维清《上海乡土志》

   Tom and Gina usually go to school by car .They drive(驾车) pasta cinema a supermarket a post office. The post office is next to the supermarket on Center Street .Mary and Ann usually go to school by bus. They go down Sixth Avenue, past a bank and a library. The bank is across from the library. Jenny usually goes to work by bike,he rides(骑车) past a hotel and three streets．

用方框中所给单词或短语的适当形式填空。