DF4B型内燃机车硅整流装置每一桥臂上由（）整流元件并联而成。
A、4个
B、6个
C、8个
D、7个
参考答案：B
He is now _____, so he has to look for a job in a short time. Otherwise, his family will face the trouble of
lacking money. [ ]
A. at work
B. out of work
C. for work
D. on the way to work
加清钞人员双人在（）的护送下，前往加钞地点。
A.押运人员；
B.负责人；
C.保卫人员；
D.现金中心
