Ответ:
1. You must read in bed.
You mustn't read in bed.
Must you read in bed?
2. You can cross the road when the lights are red.
You cannot cross the road when the lights are red.
Can you cross the road when the lights are red?
3. You should open the window. It is cold outside.
You shouldn't open the window. It is cold outside.
Should you open the window? It is cold outside.
4. Students may shout at the lessons.
Students may not shout at the lessons.
May students shout at the lessons?
5. Parents must obey their children.
Parents mustn't obey their children.
Must parents obey their children?