Using World database on MySQL Server as the sample database, write SQL statements to solve the following questions (5points/each).

6. List all the countries in North America, and sort the result first by region, and second by surface area in descending order.

7. Find out what is the official language in USA, Canada, China, Mexico, and Brazil.

8. Find out the city that has the largest population in China (need to display both the name of the city and the population).

9. Find out the city that has the lowest population in the USA (need to display both the name of the city and the population).

10. Find out the top 10 cities that have the largest population in the USA (need to display both the name of the cities and the corresponding population).

The world database is found online but I just need the sql statements. Please and Thank you!