1. Write a or an.

1. Write a or an.

• 1. a book
• 2. an old book
• 3. a window
• 4. a horse
• 5. an airport
• 6. a university
• 7. an organisation
• 8. a restaurant
• 9. a Chinese bar
• 10. an Indian bar
• 11. an accident
• 12. a bad accident
• 13. a question
• 14. an important question
• 15. a humburger
• 16. an hour
• 17. an economic system
• 18. a nice evening