A. What does this sign say?
1. No one is in the room.
2. No one will disturb you.
3. Do not knock on the door or go inside.
4. People are not allowed in this area.
B.who might put up this sign?
1. A hotel guest wanting to relax
2. A librarian warning users not to annoy others
3. A teacher telling her students to keep quiet
4. A manager leaving his office