一心不可二用。

You can't do two things at once.

It's not possible to do two things at once.

It isn't possible to do two things at once.

Source: Tatoeba

这是因为你总是全身心处理每一件事情，没有让鸡毛蒜皮的问题分散了你的目标。

This is because you approach everything as a total person, with no loose ends hanging out to signify divided intentions.

Source: Tatoeba