Everyone wants to reduce pollution. But the pollution problem is as complicated _________ (1) it is serious. It is complicated because much _________ (2) is caused by things that benefit people. For example, exhaust _________ (3) automobiles causes a large percentage of all air pollution. _________ (4) the automobiles provide transportation for millions of people. Factories _________ (5) much of the material which pollutes air and water, but factories give employment to a large number of people.
Thus, to _________ (6) 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 _________ (7) reduced in several ways. _________ (8) and engineers can work to find ways to lessen the _________ (9) of pollution that such things as automobiles and factories cause. Governments can pass and enforce laws that require businesses and individuals to stop, or cut _________ (10) on certain polluting activities.