The new librarian still doesn't know ______ the out of date newspapers and magazines.

A．what to deal with

B．how to deal with
C．how to do with


D．what to do away with

如果完全垄断厂商通过实行价格歧视剥夺了全部消费者剩余，这种价格歧视被称为（）。

A.一级价格歧视

B.二级价格歧视

C.三级价格歧视

D.一级和二级价格歧视