来来来!英语

问题描述:

来来来!英语
______his telephone number,she had some difficulty getting in touch with bill
A,Not knowing
B,NOt having known
说明理由,

A,主句为过去时,但是分词结构所表示的动作和主语的动作并没有强调先后关系,因此分词结构不可用过去完成时.