It is twenty years since I have seen her

It is twenty years since I have seen her it is three years since i have seen him it was years before i had seen her 和it wasyears since i had It is 5 years since I have lived here.It is 5 years since I It is two weeks since I have seen him.( have seen-- saw) It was years since i had seen her.此处为什么是had seen ,可否用saw代替. I saw her five years ago,since when I haven't seen her 定语从句的 It is ten years _____ I last saw her. A. after B. since C. f It has been a month since I have seen you. Since I have seen you it is two years since we have met 和it is two years since we I have not seen her since 1997保持原句意思 I saw her was in1977