—— 请按键盘 空白键 开始游戏 ——

坚持是数学研究的关键,许多伟大的成果来自于长期的奋斗。
"A mathematician is a device for turning coffee into theorems."
The paper industry has a responsibility to lead the way in environmental stewardship.
书籍是最安静、最恒久的朋友;它们是最易接近、最睿智的顾问,也是最耐心的老师。