It is a long time since I saw my sister .

It is a long time since I saw my sister . It is a long time since i saw my sistter ( )17.—It’s a long time since I saw my sister.—_________ her it's a long time since i last saw you It's a long time since i saw you last. It has been a long time since i saw you last time. it is quiet a long time since i ----(hear)from my cousin 1.It's a long time since I left my hometown.A long time __ _ It's been a long time since I last saw a film.还是It's a long it is a long time since l last saw you__________ 为什么填at Mrs. it's a long time since i last saw you这句话有错误么 It's a long time since i saw you last 这句中的it是不是形式主语?