The crazy fans _______ patiently for two hours, and they would wait till the movie star arrived.

A．were waiting

B．had been waiting

C．had waited

D．would wait

发动机引气偏置传感器是什么结构的传感器（）

A.单文氏管式

B.双文氏管式

C.皮脱管式

D.拉瓦耳喷管式