I want to ask about two sentences, and what would be the correct way to form a question:
It's very important that we eat healthy food, ...........?
- Which would be the correct question tag: (isn't it) or (don't we)?
It's a must that all applicants follow the rules of the competition, ..........?
- Which would the correct question tag: (isn't it) or (don't they) or (mustn't they)?
Please could you tell me the correct answers, and, more importantly, why those are correct?