[填空题]
Read the following text and fill each of the numbered spaces with ONE suitable word.
Write your answers on ANSWER SHEET 1.

Pollution is a "dirty" word. To pollute means to contaminate--topsoil or something by introducing impurities which make{{U}} (31) {{/U}}unfit or unclean to use. Pollution comes in many forms. We see it, smell it,{{U}} (32) {{/U}}it, drink it, and stumble through it. We literally lived in and breathe pollution, and{{U}} (33) {{/U}}surprisingly,it is beginning to{{U}} (34) {{/U}}our health,our happiness,and our civilization.
Once we thought of pollution{{U}} (35) {{/U}}meaning simply the smog—the choking, stinging, dirty{{U}} (36) {{/U}}that hovers over cities. But air pollution, while it is{{U}} (37) {{/U}}the most dangerous, is only one type of contamination among several{{U}} (38) {{/U}}attack the most basic life functions.
Through the uncontrolled use of insectici