单选题 I regret ______ harder at office.
A) not to have worked B) not having worked C) not have worked D) having not worked

【正确答案】 B

【答案解析】regret遗憾；抱歉。后面既可以跟不定式强调将要发生的事情，也可以跟动名词强调已经发生的事情，如：I regret spending so much money on a car，我后悔在一辆小汽车上花这么多钱。I regret to say I cannot come.很抱歉，我不能来了。