—— 请按键盘 空白键 开始游戏 ——

The study of mathematics is a constant dialogue between the concrete and the abstract.
Program testing can be used to show the presence of bugs, but never to show their absence!
农时:指春耕、夏耘、秋收三个时令。与其等灾荒来了再想办法补救,不如早防备灾荒,而防备灾荒最好就是抓住农时。
I'm the reason your eyes won't see.