Sam met Mary in England and visited her school.为什么用met,不用had met?两个过去的动作为什么不用过去完成时啊?

Sam met Mary in England and visited her school.为什么用met,不用had met?两个过去的动作为什么不用过去完成时啊? Sam is in Grade Three.Mary is in Grade Two.(合并成一句）Sam and Mary is in ___ ___.只有两空 yesterday l went to the park with sam and amy .we met john in the paek. I met Mary in the street yesterday 改为强调主语I met Mary in the street yesterday改为强调主语的结构 The English corner in the People'sPark ia ____he first met Sam,an American boy.A.where B.in which I _____ Mary in the street yesterday,we ____each other since i left school.A.met；didn’t see.B.had met；hadn’t seen.C.met；haven’t seen D.met ;hadn't seen. Is Sam in,please? 我是昨天在商店遇见的玛丽 用英语怎么说什么 was yesterday 什么 i met Mary in a store When I met Mary in the street,she always___at me.A.smiled B.has smiledC.was smilingD.smiles It was I ---met Mary in the street yesterday.强调主语 昨天是我在街上遇见马力的 It was in the factory----his father worked for 10 years ----i met Mary for the first time. I （）Mary in the street yesterday,we （）each other since I left school.【答后给分】.A.met；didn’t see.B.had met；hadn’t seen.C.met；hadn’t seen.回答并附上原因. When I met Mary in the street,she always___at me.A.smiled B.has smiledC.was smilingD.smiles请问为什么呢?有没有特殊的语法? Imet MARY in 1976.we haven't met each other___.A.since ever B.from then on C.ever since D.after that 为何选C? It ( ) an od begger ( ) Mary met in he street yesterdayA was which B was whom选的是B为什么不是A 强调句 Mary met Jhon in the factory yesterday 改为强调句,分别强调地点和时间各用 it was.was it.who was it that.三种形式 I ___ Mary in the street yesterday ,we ___ each other since I left school.A.met;didn't see B.had met;hadn't seen C.met;haven't seen D.met;hadn't seen答案上说是C,我觉得应该是D啊?谁能给我讲一下?还有一题：They are sitting _ I met Mary,and she lent me 10.It___the money.