—— 请按键盘 空白键 开始游戏 ——

Mathematics is not just a collection of abstract theories, but a language that describes the universe.
黄莺和鲜花尚且担心春光流逝,怎么可以白白虚度大好时光?
The challenge of our time is to create a sustainable energy future.
Education is the seed from which sustainable forestry practices grow.
可持续性不是一个流行词,而是我们行业未来的基础。