Answer: C) Mustn't
Explanation for this question is being written.
Answer: A) Must
Answer: A) Mustn't
Answer: C) Must
Answer: B) Mustn't
Answer: B) Must study.
Answer: B) Must
Answer: B) Sign in at the front office.
Answer: B) To express obligation.
Answer: D) Is bound.
Answer: B) False-as well as class work, you MUST use the additional study materials given to you.
Answer: A) Must leave by 6 p.m.
Answer: B) B
Answer: B) Obligation
Answer: A) Must not.
Answer: B) Contracted negative form.
Answer: A) Mustn't wear.
Answer: B) B must.
Answer: B) You aren't allowed to do something.
Answer: D) Very important or necessary.
Answer: D) I must and I will!
Answer: B) It is essential.
Answer: D) Must be.
Answer: A) Have to / must.
Answer: A) Don't have to.
Answer: D) Mustn't
Answer: A) Had to.