Learning without thinking is useless, thinking without learning is dangerous. Learning is like sailing against the current. If you don't advance, you will retreat. If there is a threesome, there must be a teacher. If you choose a good one, follow it. If you don't choose it, change it. There is a road study in Shushan, and there is no end to domestic study. No one wants you for 50 years, and you will be famous all over the world. 6 black hair doesn't know how to work early, but white hair knows how early it is.