it is ...since it was...before 一定是过去式吗?

寻找一首歌,开头歌词是wa wa way,it is a wa wa way. as it's reported,it is more than 150 years__big beb,a famous attraction in london,wa founded.为什么填 since It is five years since he smoked it is ...since it was...before 一定是过去式吗? is this your watch?为什么回答no, it isn't.it's her wa it is ...since ..为什么不用完成时it is 100 years since Qinghua university was found. 谁知道这首网络歌曲,歌词大概it is wa wa with when you feel in .是一首轻快的歌曲 为啥it is some time since与it has been some time since没区别 it is some time since+...与it has been some time since+...什么区别? 什么时候用It was+一段时间 +since,什么时候用It is +一段时间+since? since it anyway,it is still my home,because It is my life.翻译成中文 My friend has worked in that hospital_________.A.since it opened B.for it opened C.since it opens D.since it is opentell me why? It is years since we meet last time.（纠错） It is +一段时间+ since【用的是什么时态?】 It is three years since she was in the It is/has been + since sb + 具体,简洁. It is ten years since he ____(join) the army It is+时间段+since+时间点.可以说一个例句吗？