Not only his parent but also his uncle () there before

题目

Not only his parent but also his uncle () there before
A has been
B had been 为什么不选B

答案

这里没有过去的过去,没有表示两个动作的先后关系
只有一个before 的表示现在完成时的概念
因此只能用现在完成时
过去完成时,必须在有两个动作,其中一个是过去式,另一个动作在这个过去式之前体现,此题中不是