在杆上作业时，除有关人员外，不得他人在杆下面（）或逗留，防止落物伤人。
A.通过
B.站立
C.休息
D.向上看
参考答案：A
— Dad, can you tell me why so many students choose to study abroad at a very young age?
— _ ___,darling. I have never thought about it. [ ]
A. Take your time.
B. You've got me there.
C. Don't be silly.
D. Bad luck.
抢护管涌的常见形式之一是( )。
A．黏土反滤围井
B．砂石反滤围井
C．土工织物反滤围井
D．反滤层压盖
