单项选择题
A.6 B.8 C.10 D.12
A.bh<1.550m,hh<2.375m B.bh<1.815m,hh<2.45m C.bh<1.750m,hh<2.450m D.bh<1.750m,hh<2.375m
A.61000 B.61500 C.61700 D.62000