admission is free的用法和样例：
- Admission is free on presentation of this card.
- Admission is free for all festival activities.
- Admission is free on presentation of this care.
- RSVP is NOT required to attend this concert. Admission is free of charge.
- Admission Fee Admission is free of charge with the buyer's badge, which is only offered to industry insiders aged over 18 with business cards.