she regretted_____(sell) the farm at such a low price为什么答案是having sold而不是selling

问题描述:

she regretted_____(sell) the farm at such a low price
为什么答案是having sold而不是selling

regret to do 是遗憾做某事
regret doing 是后悔做某事,这里她已经买了,所以用完成时.