A.25% B.50% C.75% D.100%
A.普通硅酸鹽水泥 B.礦渣硅酸鹽水泥 C.火山灰質(zhì)硅酸鹽水泥 D.粉煤灰質(zhì)硅酸鹽水泥
A.16mm B.20mm C.25mm D.30mm