单项选择题
A.氯丁橡胶 B.丁基橡胶 C.丁腈橡胶 D.氟橡胶
A.55% B.65% C.75% D.80%
A.≤1mg/l B.≤5mg/l C.≤10mg/l D.≤15mg/l
A.酸浓为2mg/l B.酸浓为2g/l C.溶液中H+浓度为10-2M D.溶液中H+浓度为102M
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