a voucher for children's glasses的用法和样例：
- Passengers can obtain a voucher for refreshments from the information desk.
- Each guest is offered a voucher for a complimentary drink from the bar.
- Kindly sign it and return to me, so I can put through a voucher for the $1000 we agree on.
- "We're going to Jacksonville?" And I was excited, in spite of myself. It was a voucher for plane tickets, for both me and Edward.