The beauty of mathematics lies not only in its abstract elegance but also in its profound ability to model and solve real-world problems.
事实是:自然界正在变化。而我们完全依赖那个世界。它提供我们的食物、水和空气。它是我们拥有的最宝贵的东西,我们需要捍卫它。
人们为了保护自己不受伤害,会伤害他人。