The school I miss very much # is an adjective phrase used to describe someone's great desire and yearning for the school or educational institution in his mind. This sentence conveys a strong desire and yearning for an ideal school.

Outstanding advantages

This phrase is usually used to express yearning for a particular school, probably because it has advantages in academics, environment and facilities.

value matching

Or because this school conforms to personal interests, goals and values.

Strong yearning and expectation

Therefore, if someone mentions "the school I miss very much", it may be expressing strong yearning and expectation for a school, hoping to have the opportunity to study in this school.