题目内容
Read the passage carefully and then answer the questions or complete the statements in no more than ten words.
A rain forest is an area covered by tall trees with the total high rainfall spreading quite equally through the year and the temperature rarely dripping below 16. Rain forests have a great effect on the world environment because they can take in heat from the sun and adjust the climate. Without the forest cover, these areas would reflect more heat into the atmosphere (大气), warming the rest of the world. Losing the rain forests may also influence wind and rainfall patterns, potentially causing certain natural disasters all over the world.
In the past hundred years, humans have begun destroying rain forests in search of three major resources: land for crops, wood for paper and other products, land for raising farm animals. This action affects the environment as a whole. For example, a lot of carbon dioxide (二氧化碳）in the air comes from burning the rain forests. People obviously have a need for the resources we gain from cutting down trees but we will suffer much more than we will benefit.
There are two main reasons for this. Firstly, when people cut down trees, generally they can only use the land for a year or two. Secondly, cutting large sections of rain forests may provide a good supply of wood right now, but in the long run it actually reduces the world's wood supply.
Rain forests are often called the world's drug store. More than 25 percent of the medicines we use today come from plants in rain forests. However, fewer than 1 percent of rain forest plants have been examined for their medical value. It is extremely likely that our best chance to cure diseases lies somewhere in the world's shrinking rain forests.
73.Why can rain forests help to adjust the climate?
74.What may be directly influenced according to the first paragraph if we lose the rain forests?
75.The underlined word "this" in the third paragraph refers to ________________________________________________.
76.Rain forests are often called the world's drug store because ___________________________________________ are from plants in rain forests.
73 Because they can take in heat from the sun.
74 Wind and rainfall patterns.
75 we will suffer more than we will benefit.
76 more than 25 percent of the medicines we use today
