I took the liberty of borrowing your lawn-mower while you were away.
你不在的时候我擅自借用了你的刈草机。
I am afraid that I am not at liberty to discuss this matter.
对不起,我无权讨论这个问题。
I took the liberty of reading the letter, even though it was addressed to you.
尽管这封信是写给你的,但是我冒昧地看过了。