Without ____ participation of so many people, the completion of such a project in a short period would be out of ______ question.

A．a; /

B．the; /

C．a; the

D．the; the

砌体房屋必须设置圈梁，圈梁设置的位置是（）。

A.外墙四周

B.所有内墙

C.所有外墙和内墙

D.外墙和部分墙