The writing is full of little inaccuracies- most of the people/most people, the comma after quiet, the missing article before 'crowded environment', the unnatural phrasing of 'if it is unnecessary', etc. However, they're getting their basic point across. When you ask for level, it's hard to answer without knowing the levels you are using. I'd call this intermediate, but a lot depends on the system, the outcomes, exams, etc.
- For Teachers