在封建社会,()每三年一次在省城举行,取中者称“举人”。
A、会试
B、院试
C、乡试
D、殿试
参考答案:C
My brother is an actor. He ______ in several films so far.[ ]
A. appears
B. appeared
C. has appeared
D. is appearing
钨极氩弧焊要求采用具有()或恒流外特性的电源,以减小或排除因弧长变化而引起的电流波动。
A.陡降
B.上升
C.缓降
D.平硬