Shoota
2020-11-23T04:32:10+00:00
第一题，难道不会出现pp’c怎么都不共线的情况吗，都不需要证明吗[s:ac:晕][s:ac:晕][img]https://img.nga.178.com/attachments/mon_202011/26/-7Q5-i7oaK28T1kSg0-sg.jpg.medium.jpg[/img][img]https://img.nga.178.com/attachments/mon_202011/26/-7Q5-26ivZbT1kSg0-sg.jpg.medium.jpg[/img]