JellySandwich
2022-08-10T03:16:40+00:00
凭常识来说,好理解
但是怎么用数学解释呢[img]https://img.nga.178.com/attachments/mon_202208/12/-7Q2q-ekkyK1hT3cSlc-sg.jpg[/img]
但是怎么用数学解释呢[img]https://img.nga.178.com/attachments/mon_202208/12/-7Q2q-ekkyK1hT3cSlc-sg.jpg[/img]