III. Read the following passage. Decide if the statements from 17 to 20 are True or False, and choose the correct answers (A, B, C or D) for question 21 and 22.
Everyone wants to reduce pollution. But the pollution problem is as complicated as it is serious. It is complicated because much pollution is caused by things that benefit people. For example, exhaust from automobiles causes a large percentage of all air pollution. But the automobile provides transportation for millions of people. Factories discharge much of material that pollutes air and water, but factories give employment to a large number of people.
Thus, to end or greatly reduce pollution immediately, people would have to stop using many things that benefit them. Most of the people do not want to do that, of course. But pollution can be gradually reduced in several ways. Scientists and engineers can work to find ways to lessen the amount of pollution that such things as automobiles and factories cause. Governments can pass and enforce laws that require businesses and traffic to stop, or cut down on certain polluting activities.
