單項選擇題我國飲用水衛(wèi)生標準規(guī)定出廠水接觸30分鐘后余氯不低于();在管網末梢不應低于()。

A.0.2mg/L,0.04mg/L
B.0.3mg/L,0.05mg/L
C.0.4mg/L,0.06mg/L
D.0.5mg/L,0.07mg/L


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