It is +段时间＋since+主语＋did.请比较：

It is +段时间＋since+主语＋did.请比较：
It was +段时间＋since+主语＋had done.如：
It is five years since he left here.他已经离开这儿五年了.
It was five years since he left here.（同上）
请问第二句不是应该用it was five years since he had left here
It is five years since he lived here.他从这儿搬走已经有五年了
这句话为什么是这么翻译