Choose the correct articles

1. My daddy is
   [a|an|the|—]
   doctor.
2. We saw
   [a|an|the|—] elephant at the zoo.
3. I have
   [a|an|the|—] hour before my classes.
4. Kathy has got
   [a|an|the|—] cat.
   [A|An|The|—] cat is black.
5. We go to
   [a|an|the|—] school five days a week.
6. Marta can play
   [a|an|the|—] piano.