企业系统规划(BSP)方法将企业的战略转化成信息系统的战略，以下哪个不属于其转化的内容

A． 信息系统的目标

B． 信息系统的策略

C． 信息系统的总体结构

D． 信息系统的环境

Tony ________ full marks, but he was so careless as to make a spelling mistake.

A．could have gained

B．can have gained

C．must have gained

D．must gain