题目内容：

He has studied English for 6 years改为同义句
改为同义句：
He has studied English ______ ______

优质解答

He started to study English 6 year ago.
It's 6 years since he started to study English.
Six years has passed since he started to study English.
希望我的回答能够帮到你,
刚看到你的问题补充,横线上填 6 years
for 后接一段时间时,for 可以省略.