"I am not a language, I am a word."

"We are all apprentices in a craft where no one ever becomes a master."

Natural experiments are a powerful tool for understanding causal relationships in the real world.

The thing that is important is the thing that not seen… It is just as it is with the flower。 If you love a flower that lives on a star， it is sweet to look at the sky at night。 All the stars are abloom with flowers…