It is often very difficult to distinguish between the two.

这两者时常很难去区分。

youdao

It has, until recently, been very difficult to distinguish between the two.

直到最近以前，要区别开这两者是非常困难的。

youdao

It has, until recently, been very difficult to distinguish between the two.

直到最近以前，要区别开这两者是非常困难的。

youdao