She is worried about her maths homework.在这句话中,为什么要用worry的过去形

She is worried about her maths homework.在这句话中,为什么要用worry的过去形 She was worried about her maths.的同义句She ____ ____ her maths there is nothing to worry about这句话后面为什么不能换成 to be worried? there is nothing to worry about这句话为什么后面不能用 to be worried abo she is worried about her sick mother 单词辨析worry ,worriedhe is worried about his son一句中为什么不用worry而用 i'm much worried about her health 为什么的worried 要加ed?...这是什么时态 be worried about中worried为什么是过去分词的?为什么不是过去式也要加ed? worry的问题worry不是及物动词吗?为什么有时候要加about有时候不要?还有,worried about和 wo she is worried about her son----what he said worry about和worried about的区别 worry about与worried about的区别