— Why didn't you go to the cinema yesterday?  

— I ____， but my wife returned from France the moment I was leaving.

A．was going to

B．would

C．did

D．had

为了测定矿浆浓度，对矿浆浓度的取样通常采用（）取样方法。

A、断流截取法

B、横向截取法

C、探管取样

D、纵向截取法