The man sitting next to me on the plane was very nervous..

题目

The man sitting next to me on the plane was very nervous..
It was his first flight.He ____(never,fly) before.
为什么用had never flown 不用has never flown

答案

had never flown 是过去完成时
也就是"过去的过去",相对于
it was的时候,再住前,不能用现在完成时.
如果是it is ,用has never flown