The indefinite article a/an

We use the indefinite article a/an

With singular countable nouns, when referring to something general or non-specificI’d like a coffee and a sandwich.I haven't got a pen.

With these numbers: 100, 1000, 1.000.000There were over a thousand people at the conference.

With jobsMy brother is a doctor.

1. _ moon goes around _ earth every 27 days.

2. The Soviet Union was _ first country to send a man into space.

3. I'm not very hungry – I had _ big breakfast.

4. It was a long voyage. We were at _ sea for four weeks.

5. _ Second World War ended in 1945.

6. There was _ time when I enjoyed skating.

7. People only have parks, where they can enjoy _ nature.

8. I'm tired. I think I'm going to _ bed.

9. Carol's father works as _ electrician.

10. Have you ever visited _ Tower of London?