3. what is one common purpose for writing a diary?\no to record news events\no to persuade others to agree…

Brief Explanations:

A diary is a personal record. It is mainly used to record one's own daily life experiences, feelings, thoughts, etc. Recording news events is more the function of news media. Persuading others is the purpose of persuasive writing. Offering opinions about others is just a possible part of a diary, not the most common and core purpose. While recording daily events is a very common and basic purpose of writing a diary.

Answer:

to record daily events