单项选择题
A.0.5m B.0.6m C.1m D.1.5m
A.2个及以上,2个及以上 B.2个及以上,3个及以上 C.2个及以上,4个及以上 D.3个及以上,3个及以上
A.1层,1m,100mm B.2层,1m,150mm C.2层,1m,200mm D.1层,1m,200mm