—— 请按键盘 空白键 开始游戏 ——

Mathematics knows no races or geographic boundaries; for mathematics, the cultural world is one country.
数学不知道种族或地理边界;对于数学来说,文化世界是一个国家。
可持续捕捞不是一种选择,如果我们想保护海洋生态系统,这是唯一的前进方向。
Sustainability must be at the core of every stone we extract, or we extract nothing at all.