Ответ:
1. How many languages do the people living in Melbourne speak?
2. Children must drink much milk.
3. Why he must work so much?
4. There wasn't much happiness in his face.
5. Not many new ideas were discussed.
6. We shan't have many lessons tomorrow.
7. I won't have many mistakes in this exercise.
8. We didn't take much food with us.
9. There aren't many new subjects this year.
10. I haven't much free time today.
11. He doesn't do many written exercises every day.
12. We don't drink much coffee in our family.
13. There isn't much furniture in my room.
14. I don't take much money to school.
15. There are many new houses in the street.
16. There are not many shops in our street.
17. Don't put much sugar in my tea.
18. Do not drink much coffee in the evening.
19. There is much snow in winter in Russia.
20. He does not eat much.