单项选择题
A.二级; B.一级; C.三级; D.视场地复杂程度确定.
A.27.82m/d B.36.49m/d C.40.75m/d D.51.43m/d
A.0.912 1.5g/cm3 1.85g/cm3 B.0.912 1.6g/cm3 1.85g/cm3 C.0.819 1.6g/cm3 1.95g/cm3 D.0.819 1.5g/cm3 1.95g/cm3