3. Use should / shouldn't:
Occupy this seat, please — You should occupy...
Don't do it - You shouldn‘t do it. '
l. Comfort your children, please.
2. Don't smoke, please.
3. Don't keep you bag here, please.
4. Don't put heavy things on the rack, please.
5. Don't walk, please

1. You should comfort your children.2. You shouldn't smoke.3. You shouldn't keep your bag here.4. You shouldn't put heavy things on the rack.5. You shouldn't walk.