Most people always think that when they are old, their memory ability must be poor. Actually, it's not. Please look at the experimental results. The International Linguistic Society made a comparison between young people aged 9 to 18 and adults over 35 in learning Esperanto, and found that the former was inferior to the latter in memory. This is because adults are rich in knowledge and experience, and it is easy to establish extensive contacts on the basis of existing knowledge. Psychologically, it is called "association". People's memory is based on association. The richer their knowledge and experience, the easier it is for them to establish associations and their memory will be improved accordingly. When Marx was in his fifties, he began to learn Russian. After half a year, he has been able to read the original works of famous poets and writers Pushkin, Nikolai Gogol and Schederin with relish. This is because he has rich language knowledge and can be familiar with many modern and ancient languages.

(2) classification. According to the country, there are Chinese and foreign books in the library; According to the times, there are classical and modern; By nature, there are science and technology, literature and political economy.

(3) Column data.

By contrast, this place is as big as two basketball courts.

(5) draw a chart.

(6) definition. Man is an advanced animal, who can make tools and use them for labor.

Fertilizer is a substance that can supply nutrients and make plants grow.

Overall planning method is a mathematical method to arrange the work process.

(7) interpretation. For example, the phrase "man is a senior animal who can make tools and use tools for labor" is changed to "the senior animal who can make tools and use tools for labor is a man", and the meaning remains unchanged. The sentence "Snow is solid precipitation formed in clouds" cannot be changed to "Snow is solid precipitation formed in clouds". Therefore, it can be distinguished that the former sentence is a definition and the latter sentence is a description.

For example, when autumn comes, maple leaves are like red fire.

(9) imitation.

"The Great Wall of Wan Li has no head before it and no tail after it."

(10) reference. Zhang said in the Tang dynasty that it was "made strangely, and people don't know why." -Stone arch bridge in China.