单项选择题
A.20~30mm B.50~100mm C.60~80mm D.40~50mm
A.0.4m B.0.6m C.0.8m D.1m
A.1皮混凝土小型空心砌块 B.2皮混凝土大型空心砌块 C.1皮烧结普通砖 D.3皮烧结普通砖