—— 请按键盘 空白键 开始游戏 ——

每个数学问题都有一个解决方案;只是需要时间和努力去找到它。
"The act of writing is an act of optimism. You would not take the trouble to do it if you felt it didn't matter."
你必须对自己有耐心,并相信这个过程。