Please refer to:

Living with good people is like entering a house of orchids. If you don’t smell its fragrance for a long time, you will be transformed into it; living with unkind people is like entering a house of abalones. , if you smell the odor for a long time, you will also be transformed into it. The red color is hidden in the elixir; the black color is hidden in the lacquer. Therefore, a gentleman must be careful where he is.

The odor is also transformed into it. That’s it. What is hidden in elixir is red, and what is hidden in lacquer is black. Therefore, a gentleman must be cautious about where he is.

Assimilate, assimilate, and become consistent with...

In other words, the pronoun refers to Zhilan (abalone) in the previous text

Yes, it cannot be explained alone. Together with the word "Yi", it is interpreted as: therefore; therefore

The person who...

So being with people of high moral character is like bathing in a room full of fragrance from orchids. After a long time, you will no longer smell the fragrance, but it is already full of fragrance; and with poor conduct When people are together, it's like going to a place selling abalone. After a while, you no longer smell the smell, and you blend into the environment; the place where the elixir is hidden turns red over time, and the place where the paint is hidden turns red after a long time. Black is also due to environmental influences! Therefore, a true gentleman must carefully choose his environment.

Additional: The one who is close to vermilion is red, and the one who is close to ink is black.