切片输送前，切片缓冲罐、合格切片储罐、不合格切片储罐处于（）状态。
A、关闭
B、受料
C、送料
D、其他
参考答案：B
—It’s very hot in the room! --_______ the door open?
A．Why don’t keep
B．Why don’t to keep
C．Why not keep
D．Why not you to keep
蒸汽品质的调节方法？
