A、0.2~0.4m B、0.2~0.5m C、0.3~0.5m D、0.3~0.6m
A、不應(yīng)少于60min B、不應(yīng)少于70min C、不應(yīng)少于90min D、不應(yīng)少于180min
A、混凝土預(yù)制塊 B、鋼骨架 C、漿砌片石骨架 D、木骨架