Many students believe the choice of their courses and universities should____ __ their own interest.

A．be based on

B．base on

C．be basing on

D．base at

下列各项中，不属于原始凭证要素的是( )。

A．经济业务发生日期

B．经济业务内容

C．会计入员记账标记

D．原始凭证附件