1, sick. Illness is the best reason to ask for leave, but any cold, headache, diarrhea, vomiting or acute appendicitis can be used as a reason to ask for leave.

2. Family affairs. There are important things at home, such as getting married, which is also a good reason to take time off.

3. Tell the teacher the truth about asking for leave. In fact, the reason why teachers don't approve vacations is that students are afraid of any accidents when they go out. If they don't know where they are, it's hard for them to explain to their parents and schools. So tell the truth to the teacher, tell him that he really needs to ask for leave, and tell him the truth no matter what the teacher asks.

Extended data:

Be sincere when you ask for leave, and promise the teacher that you won't delay your study. If the teacher is in a good mood when taking time off, it is better to take time off. There is also to see if there are many times of leave at ordinary times. If there are too many times, it will be a bit difficult to ask for leave. If there are not many times, it is better to ask for leave. Under normal circumstances, teachers will basically agree to take time off when they see that they are telling the truth.