—— 请按键盘 空白键 开始游戏 ——

"Books are the quietest and most constant of friends; they are the most accessible and wisest of counselors, and the most patient of teachers."
煤炭一直是工业的支柱,通过创新,它可以继续发挥作用。
"In every equation, there is a story waiting to be told."