—It’s said that your journey was not very pleasant.

—We would have enjoyed ourselves, but the car ___ a little crowded.

A．would be

B．had been

C．was

D．would have been

下列哪项不属于喷射混凝土支护作用原理（）。

A.组合梁作用

B.封闭围岩防止风化作用

C.共同承载作用

D.改善围岩应力状态