一、阅读理解:阅读下列短文,从每题所给 A、B、C、D四个选项中,选出最恰当的答案。 A Since the earliest times,trees have always been very useful and important to man who made use of them in many ways.Even today trees continue to serve man in so many ways. Trees provide man with fruits and buildings in the form of wood.Without trees it would be impossible to build houses,boats and even bridges.Furniture such as tables,chairs and beds is made of wood。 In the tropics where it is very hot all year round,trees protect man from the terrible heat.They are also used for preventing good and rich top soil from being washed away during heavy rain which are so common in the tropics. If there were no trees or plants of some kinds to hold back the soil,heavy rain would wash the rich surface soil that is SO important and necessary to agriculture.The result is that the land becomes a desert. There are so many desert areas in the world.A long time ago these desert areas must have been very rich areas,but since our ancestors in the past didn't have enough knowledge about science of nature,they cut down all the trees in the areas where they rived and never planted new ones.Soon the rich surface soil was blown away by strong winds and heavy rain.In the end,the land was turned into the deserts where nothing could grow. We Chinese don't want to see more natural disasters,so it's our duty to protect the environment.