A.0.6 B.0.8 C.1 D.1.5
A.20~30% B.24~30% C.15~30% D.25~35%
A.1/5~1/10 B.1/10~1/20 C.1/20~1/30 D.1/30~1/40
A.工业废水 B.饮用水 C.海水 D.湖水
A.略大于 B.略小于 C.等于 D.1.5倍