农时：指春耕、夏耘、秋收三个时令。与其等灾荒来了再想办法补救，不如早防备灾荒，而防备灾荒最好就是抓住农时。

If you don't like something, change it. If you can't change it, change your attitude.

The most important tool in chemistry is not the flask or the spectrometer—it's the imagination.

释义：从天下的角度看，应遵循天下的公理，天下不是某一姓的私有财产。