Ответ:

Rules for the library:

  1. Shout: X (You mustn't shout.)
  2. Be quiet: ✔ (You must be quiet.)
  3. Phone your friends: X (You mustn't phone your friends.)
  4. Eat food: X (You mustn't eat food.)
  5. Be careful with the books: ✔ (You must be careful with the books.)
  6. Run: X (You mustn't run.)