劳动制度，包括企业的（）
A.用工制度
B.生产安全管理
C.劳动时间规定
D.劳动纪律
E.奖惩制度
参考答案：B, C, D
— I dropped in at your house at about ten last night, but you weren't in.
— I ______ regular exercises at the club. [ ]
A. did
B. was doing
C. had done
D. have been doing
焊接方式分为（）。
A、平焊
B、立焊
C、横焊
D、仰焊
E、俯焊
