=>
3. What colour hair does she have?
4. School C is the biggest of three schools.
5. We have to attend the meeting.
6. You mustn't cheat at exams.
7. There isn't a computer in his room.
8. I like English most.
9. A car is more expensive than a motorbike.
10. (-) My friend doesn't go to school by bus.
(?) Does your friend go to school by bus?
11. What colour eyes does your brother have? 
12. longer -> longest
13. I should decorate my house.

3. What colour hair does she have?
4. School C is the biggest of three schools.
5. We have to attend the meeting.
6. You mustn't cheat at exams.
7. There isn't a computer in his room.
8. I like English most.
9. A car is more expensive than a motorbike.
10. 

Negative : My friend doesn't go to school by bus.

Affirmative : Does your friend go to school by bus
11. What colour eyes does your brother have? 
12. longer `->` longest
13. I should decorate my house.