A.封閉的孔隙 B.粗大開口的孔隙 C.孔隙率大、具有微細(xì)、聯(lián)通、開口的孔隙 D.粗大封閉的孔隙
A.5%~8% B.5%~10% C.10%~15% D.10%~20%
A.200 B.300 C.400 D.500