2. Fill in the article (a/an, the) where it’s necessary.
1. … Mark Twain is famous for his book “The Adventures of Tom Sawyer”
2.  … Smiths have … dog and … cat.
3. “Is this your ... friend?” — “No, it isn’t my ... friend, it is my sister”.
4. This is ... tree. ... tree is green.
5. I can see three ... children. ... children are playing in … yard.
6. What's … highest mountain in the world?
7. He lives in … Paris.
8. He is  … economist.
9. … Earth goes round … Sun.
10. What … strange girl!
11. Could you close … door, please?
12. We celebrate  New Year on … 31st of … December.
13. It is washed by the waters of … Atlantic Ocean.
14. Are you studying foreign languages at school, like … French?
15. … Moscow is on … Moskva River.