看板管理的核心原理是（）。
A.将生产计划逆流程执行
B.前后工序间的时间差最小化
C.后工序指挥前工序
D.工序间作业时间均衡分配
参考答案：C
在限速为70km/h的恒速区段运行的货物列车，当LKJ实施常用制动时，其减压量为（）kPa。
A、120
B、110
C、80
D、70
根据句意及首字填空。
1.I have to babysit my sister the w______ morning.
2. Paula is going to have a p______ to celebrate her birthday.
3. There is going to be a baseball m______ in our town next week.
4.I have a piano l______ this afternoon.
5. Can you c______ over to my house to help me with my English?
