A.≤0.1m/s B.≤0.3m/s C.≤0.5m/s D.≤0.7m/s
A.20%—45% B.40%—45% C.40%—65% D.20%—65%
A.二次供水水質應符合國家生活飲用水衛(wèi)生標準 B.二次供水水箱應定期清洗消毒 C.二次供水水箱應有衛(wèi)生防護措施 D.自備水源不必檢測