1, the habit formed by wisdom can become second nature. It is the wisdom of crocodiles to shed tears before eating others. Melon is sweetest when born in pure fertilizer, and genius is best when born in vicious soil. Natural talents are like natural plants, which need pruning through study. Cunning is an evil wit. A piece of bacon

2. Never try to cover up your knowledge defect, even if you cover it up with the boldest guesses and assumptions, it is unacceptable. No matter how bright the color of this soap bubble is, it is bound to burst, so you will only get shame. [Russia] Pavlov's A Letter to Young People (Selected Works of Pavlov), p. 3 1.

3. A person with a bottle of musk in his pocket won't go to the crossroads and shout to let everyone know, because the fragrance floating behind him has said everything. Issaadi

4. Half the truth we get by ourselves is much more valuable than all the truths we learn from others and recite like parrots. Romain rolland's Pioneer, romain rolland Banknotes, p. 79.