Rule of 7 in research. You can find out anything if you are willing to go seven levels. If the first source you ask doesn’t know， ask them who you should ask next， and so on down the line. If you are willing to go to the 7th source， you’ll almost always get your answer.

质量从来不是偶然的；它始终是智慧努力的结果。

我不是来取悦任何人的。

知识是解开宇宙奥秘的钥匙。

"The world is full of obvious things which nobody by any chance ever observes."