unforgiving
adj. 不原谅人的；不宽恕人的
例句
He was an unforgiving man who never forgot a slight.
他是一个记仇的人，一点小事也不会忘记。
《柯林斯英汉双解大词典》
Business is a competitive activity. It is very fierce and very unforgiving.
商业是一种竞争性强的活动：很残酷，也不允许任何错误。
But stone flags are unforgiving.
但是石板是无情的。
