He hesitated a moment, and then knocked on the door. 他犹豫一阵后敲了敲门。

hesitate to do sth My mother never hesitates to tell me when I look bad. 如果我气色不好，我母亲总是毫不犹豫地告诉我。

Don’ t hesitate to call me if you need any help. 你如果需要帮助，尽管给我打电话。