Вставьте неопределенный артикль, где необходимо.

1. This is… book. It is my … book. 
2. I have … sister. My …sister is … doctor. 
3. They have … dog and two … cats. 
4. There is … little brown coffee table in our … room. 
5. My … sister is at … work. 
6. There are … beautiful trees in our … park. 
7. What … nice day today! 
8. It is such … difficult task. 
9. My … mother keeps… house. 
10. We usually have … lunch at 12.