对容器口进行磨砂处理可以提高容器的密封性。下列几种仪器中，容器口没有进行磨砂处理的是[ ]

A.广口瓶

B.锥形瓶

C.滴瓶

D.集气瓶

Not until the train pulled into the station          that his suitcase was gone.

A．had he found

B．did he find

C．he had found

D．he found