Learning is any change in a system that produces a more or less permanent change in its capacity for adapting to its environment.
学习是系统中产生的任何变化，这些变化或多或少会永久性地改变其适应环境的能力。
书籍是连接我们彼此的桥梁。
Mathematics is a living, breathing discipline, constantly evolving with new ideas.
有时候最简单的想法是最有力的。