These people are animals and what they did was unforgivable.
这些人是禽兽，他们所做的一切都是不可原谅的。
Is every accounting technique used by a corporation unforgivable?
来自THETIMES
Being late is an unforgivable sin round here.
迟到在这里是一种不可原谅的失礼行为.
I also suspect that I'm becoming a bore, which is something unforgivable in anybody, but especially in a journalist.
我还怀疑自己正在变成一个令人厌恶的人，这对任何人来说都是不可原谅的，对于一名记者而言更是如此。
What's completely unforgivable is the implementation, which is entirely Javascript dependent.
来自BBC
To continuously attempt to turn this country into a socialist paradise is unforgivable.
来自WSJ