文书在起草、审核、签发后所具署落款时间是（）。
A.文书针对时间
B.文书形成时间
C.收文处理时间
D.文书传递时间
参考答案：B
-Well，I do think the ipod is smart，convenient and intelligent．
-________．
A．So it is
B．So is it
C．So does it
D．So it does
For price discrimination to work, the seller must face a market with all of the following characteristics EXCEPT:（）
A. high barriers to entry.
B. a downward sloping demand curve.
C. two or more identifiable groups of customers with different price elasticities of demand for the product.
