Everyone wants to reduce pollution. But the pollution problem is (1) **as** complicated as it is serious. It is complicated (2). much pollution is caused by things that benefit people. For example, exhaust (3). automobiles causes a large percentage of all air pollution. But transportation for millions of people. Factories discharge much (4) **pollution** that pollutes the air and (5) **water**.but factories give employment to a large (6) **number** of people. Too much fertilizer or pesticide can ruin soil, but (7) **proper** fertilizers and pesticides (7) **are** the important aids to the growing of crops. Thus to end (8) **pollution** greatly reduces pollution immediately people would have to (9) **stop** things that benefit them. Most people do not want to do that, of course. But pollution can (10) **be** gradually reduced in many ways.