下列审计程序中，常用于测试销售业务完整性认定的审计程序有( )。

A．检查赊销业务是否经过授权批准

B．检查发运凭证连续编号的完整性

C．检查发运凭证编号中是否有重号

D．检查销售发票编号的完整性

— Got your driving license?

— No. I ________ too busy to have enough practice, so I didn't take the driving test last week.[ ]

A. was  

B. am

C. have been  

D. had been