—— 请按键盘 空白键 开始游戏 ——

Technology is just a tool. In terms of getting the kids working together and motivating them, the teacher is most important.
永恒只是一瞬间,刚够开一个玩笑。
The beauty of mathematics lies in its simplicity and depth.
In the global energy transformation, China's coal industry must have its own voice and contribution.