--four years since I joined the army.A.There was B.There is C.It was D.It is选个为什么请分析C和D
问题描述：
--four years since I joined the army.A.There was B.There is C.It was D.It is选个为什么请分析C和D
答
选D,it is+time+since+V,固定搭配,意思是自从没做***已经多久了
选C是错吧它当作强调句,好像是的,不知道对不对哦