我们不是从祖先那里继承了地球，而是从我们的孩子那里借来的。
Life was simple before World War II. After that, we had systems.
成功来自于坚持和努力。
The key to credible causal inference is not just the method, but how well the method fits the question at hand.
"The best and most beautiful things in the world cannot be seen or even touched - they must be felt with the heart."