酸洗按酸的种类可分为（）
A.硫酸酸洗
B.盐酸酸洗
C.硝酸酸洗
D.氢氟酸酸洗
参考答案：A, B, C, D
Our club is open to adults only. _______your children have entered without permission. [ ]
A. There seems that
B. It seems to be
C. There seems to be
D. It seems that
涵洞的地基为压缩性土层时，其工后沉降不应大于（）。
A、20mm
B、30mm
C、40mm
