1. (2019五上·隆昌期中) 根据已有的结果找出规律，直接写得数.

6.6×6.7=44.22

66.6×66.7=4442.22

666.6×666.7=444422.22

66.666×66.667=

666.666×666.667=

6.666666×6666.667=