He has been studying Chinese for____one year.怎么填?

over.
原因是原句中用的是have been doing,而不是have done 句型.
Have been doing 是现在完成进行时,强调在一段时间内都在做某事.
所以这个句子有2种填法,
1.He has been studying Chinese for over one year
2.He has studied Chinese for only one year
PS:
另一个角度理解,have been doing 意思是一直在坐某事,强调时间较长,比如
He has been playing PC games all day!
他一整天都在玩电脑.
所以如果前面用have been doing 后面却用了表示仅仅的 only,前后语气就矛盾了.