湿法安装大理石时,基层面到大理石表面距离不小于______。
A.2cm
B.5cm
C.10cm
D.无要求
参考答案:B
A little girl sang a lot of songs to them up. [ ]
A. clean
B. cheers
C. cheer
D. cleans
闸板阀的密封性和吸料性优于S阀,因此能够适应大骨料混凝土的泵送。