单项选择题
A.4%~3% B.3%~2% C.2%~1% D.1%
A.舒乐舍板墙 B.加气混凝土砌块墙 C.烧结多孔砖墙 D.轻钢龙骨石膏板墙
A.6418 B.6480 C.6940 D.7480