精益物流的关键是：（）
A.正确认识价值流
B.价值流的顺畅流动
C.消除浪费
D.以顾客需求为动力
E.不断改进，追求完善
参考答案：D
句型转换
小题1:She often does her homework at night. (变为否定句)
She her homework at night.
小题2:We are cleaning our classroom now. (对划线部分提问)
you now?
小题3:He likes pandas because they are very cute. (对划线部分提问)
he pandas?
小题4:I think he is in the classroom.（改为否定句）
I think he in the classroom.
小题5:Mr Black is a doctor.（对划线部分提问）
Mr Black ?
低碳钢试件在拉伸过程中，应力应变曲线变化分为以下几个阶段。（）
A、比例阶段
B、颈缩阶段
C、屈服阶段
D、强化阶段
E、破坏阶段
