answer: #Person2# says there're main and small sightseeing spots and #Person1# asks for through tickets.
documents: #Person1#: Excuse me, how many sightseeing spots are there in the park?
  #Person2#: There are about 20 main spots and some other small spots.
  #Person1#: Do I have to buy extra ticket if I want to visit the main spots?
  #Person2#: Yes, some of the spots charges separately.
  #Person1#: Well, do you have through tickets?
  #Person2#: Yes, sir, it's $ 20.