Ответ:
1. We live THE Earth.
2. Many people dream about traveling in 2) space.
3. 3) Russia is situated in 4) Europe and 5) Asia.
4. There are 50 states in 6) THE USA.
5. He is going to see (7) THE Alps.
6. (8) THE Volga flows into (9) THE Caspian Sea.
7. (10) THE Bahamas are a group of islands in the Atlantic Ocean.