Wei Hua found a job ______a nurse. [ ]
A. for
B. as
C. in
答案:B
配电装置室通往防爆间隔的通道最小净宽应不小于()mm。
A.1100
B.1200
C.1000
D.800
什么是过失误差和偶然误差?各自的特点是什么?