Choose the correct options

1. I've got
   [a|an|—] sandwich.
2. This is
   [a|an|—]orange.
3. They haven't got
   [a|an|—]frisbee.
4. We like
   [a|an|—] biscuits.
5. I've got
   [a|an|—] two eggs.
6. This isn't
   [a|an|—] ball.
7. He has got
   [a|an|—] apple.