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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.

The advancement of mathematics is due to those who are driven not by the desire for application but by the joy of discovery.

老年的巨大優(yōu)勢(shì)在于你可以隨心所欲地粗魯。

"In times of crisis, true leaders emerge not by seeking power, but by serving others."