经主持竣工验收单位批准可将交工验收和竣工验收合并为一次竣工验收的工程有( )。
A.路基工程
B.涵洞工程
C.小型工程
D.小桥工程
E.简易工程
参考答案:C,D
—Shall I buy this toy for little David?
—______. He might already have it. [ ]
A. You should
B. You'd better not
C. No problem
D. You can't do that
湿喷砂的磨料由砂料与水组成。( )