1. A person who does not keep his word. Keeping one's word is the most basic rule of life. You must do what you promise others in a timely manner. Even if you can't do it, you must do a good job of explaining it. You can't break your promise.

2. Don’t make friends with people who flatter you. Some people are always good at flattering those who are better than themselves at work and life, hoping that they can help them, but people who are too flattering are not worth dating.

3. People who like to take advantage of others. Don't make friends with people who like to take advantage of you. You might take advantage of your friends at some point. Making friends is to share the joy of life and work and resolve worries. No one wants to associate with someone who just likes to take advantage of you.