31.  Third, the waste water that many factory have given off has been polluting the river .

32.  We would order that the waste water must be cleaned before it flow into rivers.

33.  They clean the waste water before it goes into rivers and plant trees.

34.  Third, factories should be equiped with high-quality facilities to clean the waste water.

35.  For example, factories give the waste water into rivers and lakes, and many field can not be watered with the poluted-water .

36.  We discharge industrial waste air, waste water and waste material at random.

37.  Large amount of waste water was discharged into the river, which used to be clear and teem with fish; the waste gas irritating the nose wantonly invaded the blue sky.

38.  They ignored the call of nature and the enviroment protection, desoultorily cutting down trees, giving off poinous gases and charging waste water into clean rivers.