单项选择题
A.2W(0.0399)m B.W(0.0399)m C.2W(0.399)m D.W(0.399)m
A.1.0m/d B.25.0m/d C.2.5m/d D.10.0m/d
A.125.53m/d B.175.25m/d C.142.65m/d D.71.35m/d