RM80型清筛机的挖掘链驱动液压系统由（）台不同的轴向柱塞油泵组成。
A、2
B、3
C、4
D、5
参考答案：A
—My teacher says she’s canceling the class play. I just can’t understand.
—______.You were looking forward to it.
A．It doesn’t matter
B．It’s very unwise of her
C．Don’t worry about it
D．You must be disappointed
劳动定额制定基本要求是多方面的，其关键是（）。教材第80页
A.快
B.准
C.全
D.多
