it was +since后面跟过去时还是过去完成时

it was +since后面跟过去时还是过去完成时 since作“自从”时,后面能跟过去完成时吗?Did Mike have a good time at the party?Yes.He said that it was years ____he had enjoyed himself so much.A.after B.since C.before D.when答案好象是B,但since不是后面都跟过去时吗?或 高一英语语法：It was long before 后面是过去时 It will be long高一英语语法：It was long before 后面是过去时It will be long before 后面跟现在时 since后面什么时候跟完成时态,什么时候用过去时态? 关于it is ...since的问题我知道it is...since时,since后加动词过去时时,is可以改成has been.那么如果it was...since的时候since后面的动词用什么呢?是had been吗?还是这个句型不对?那另一个是什么句子呢?我 it is/has been+时间段+since since后面接完成时还是一般过去?求例子详解!拜谢~ It was years since i had seen her.此处为什么是had seen ,可否用saw代替.句型不是It+is/was+时段+since+过去时? 这个句子为什么用过去时啊The house has never been rebuilt since it was burnt down.since后为什么要用过去时啊 was后面跟动词的什么形式?是过去时还是ing形式?还是其它的? 有没有it was +时间 since ...大家一定知道有It is +时间 since .请问有没有 it was +时间 since.如果有,请问it was 后面加什么?since后面加什么? It is/was +段时间 +连词（since/before）+一般现在时,一般过去It is/was +段时间 +连词（since/before）+一般现在时,一般过去时,或完成时.请哪位懂的讲一下,关于连词的固定句型 it had been a long time ,since sb was a girl.这个过去完成式,had been it happened that 后面跟过去时态还是现在时态过去时态都可以? before后面要用过去完成时是怎么个情况?since后面一定要用过去时么? it is ...since ..为什么不用完成时it is 100 years since Qinghua university was found. since一般后面跟什么时态 It was thought ful of John to send me this present.为什么前面是was后面send为什么不变过去时 as i was getting on the bus ,i slipped and hurt my foot 这句话是否能说成as i got on the bus ,i slipped and hurt my foot as什么时候后面跟过去时,什么时候跟过去进行时