Many kinds of help ________ by plane or by train to the area ever since the earthquake hit it.

A．had been offered

B．have been offered

C．are offered

D．were offered

坚持党的基本路线不动摇的关键是（）。

A．坚持以经济建设为中心不动摇

B．坚持两手抓、两手都要硬的方针不动摇

C．坚持四项基本原则不动摇

D．坚持改革开放不动摇