原式=(22)2-33+12+6×33
=12-33+12+23=1-3．
—Hi, Johnson, any idea where Susan is?
—It’s class time, so she in the classroom now.
A．can be
B．must have been
C．might have been
D．should be
下列入库存储作业原则不正确的是( )。
A．面向通道B．分层堆放C．先进后出D．形状对应
