Here are the correct answers to the sentences based on grammar rules regarding articles:

1. I would live by **the** sea. (D)
2. Harry is a sailor. He spends most of his life at **sea**. (C)
3. There are billions of stars in **space**. (D)
4. He tried to park his car but **the** space wasn’t big enough. (D)
5. We often watch **the** television. (A)
6. Can you turn off **the** television, please? (A)
7. We had **a** dinner in a restaurant. (A)
8. We had **a** meal in a restaurant. (A)
9. Thank you. That was **a** very nice lunch. (A)
10. Where can **people** buy everything they need? (D)
11. Her parents are now working in **Europe**. (D)
12. He majors in **English**. (D)
13. Mark Twain, **an** American writer, wrote "Life on the Mississippi River." (A)
14. Paris is splendid by **the** night. (C)
15. We might be able to catch **the** last train if we hurried. (C)
16. **A** used razor blade is a useless thing. (A)
17. We live at **the** third house from the church. (A)

Feel free to ask if you need further assistance!