It __is_________(be) three years since Lily joined the Green

It __is_________(be) three years since Lily joined the Green It is three years since he joined the army.为什么是用joined而不是用ha t is three years since he joined the League?it is three year It is three years since I joined the army.改成完成时态 I Gao Fang joined the League since three years ago(改为同义句） Gao Three years ____ ____ since he joined the army 填have passed John joined the army three years ago.(用since或for改写） 怎么写. 用since的话,本句应该是：It is ten years since he joined the army. It was three years ago that he joined the army与It is three y it ,three,since,years ,i ,moved,be 组成句子 It is three years since the war broke out. 1.It is two years ＿I joined the army.A.before B.since C.that