单项选择题
A.1:100~1:200 B.1:200~1:500 C.1:500~1:1000 D.1:1000~1:2000
A.1:100 B.1:200 C.1:300 D.1:500
A.倾倒式崩塌 B.膨胀式崩塌 C.拉裂式崩塌 D.错断式崩塌