Put in a/an or the in these sentences where necessary.1) Would

Put in a/an or the in these sentences where necessary.

1) Would you like apple?

2) How often do you go to dentist?

3) Could you close door, please?

4) I'm sorry. I didn't mean to do that. It was mistake

5) Excuse me, where is bus station, please?

6) I've got problem. Can you help me?