用现在分词的完成时态,表示分词的动作prepare发生在主句动作(decided)之前,相等于说:
Because the doctor had not prepared, he decided to postpone the operation.
如果直接用现在分词,分词的动作和主句的动作是同时发生的,例如:
Taking the umbrella, she rushed out of the door.
用现在分词的完成时态,表示分词的动作prepare发生在主句动作(decided)之前,相等于说:
Because the doctor had not prepared, he decided to postpone the operation.
如果直接用现在分词,分词的动作和主句的动作是同时发生的,例如:
Taking the umbrella, she rushed out of the door.