人们忘了告诉对方彼此的变化。
People change and forgot to tell each other.
 道德修养的最高境界,是认识到我们必须控制自己的思想。
Investing in lower-carbon solutions is not just good for the environment, it's good business.
数学不是关于数字、方程、计算或算法的:它是关于理解的。