单项选择题
A.加大承压面积 B.减小承压面积 C.减小对地面的压力 D.增大对地面的压力
A.2.5 B.3.5 C.6 D.8
A.4 B.3 C.1 D.2
A.一 B.四 C.三 D.二
A.200 B.180 C.160 D.150
A.200mm B.250mm C.300mm D.350mm
A.6mm B.5mm C.4mm D.3mm
A.2.0m B.1.8m C.1.5m D.2.5m
A.1/1000~3/1000 B.1/900~3/900 C.1/1000~2/1000 D.1/700~1/1000
A.2m B.3m C.4m D.5m
A.80 B.150 C.160 D.170