题目内容：

she left home two years ago 改为同义句
she left home two years ago 改为
it is two years ______she ______home
在横线上添单词

优质解答

It is two years since she left home.
或者可以说成
It has been two years since she left home.
从语法角度来讲是第二种更有理,但是第一种是已经约定俗成的用法了.