doing 和to do 可以做主语,过去分词不能作主语.当动名词doing作主语时不用它的完成时态having done.
doing 作主语表示一贯性,即经常发生的动作.to do作主语表示一次性,即将要发生的动作,如
Swimming is my favorite sport.
To clean our classroom is our task this afternoon.
doing 和to do 可以做主语,过去分词不能作主语.当动名词doing作主语时不用它的完成时态having done.
doing 作主语表示一贯性,即经常发生的动作.to do作主语表示一次性,即将要发生的动作,如
Swimming is my favorite sport.
To clean our classroom is our task this afternoon.