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.
- "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.
- The basic forms of special-purpose invoices for VAT should also include the deducting form, the invoice receiver uses it as a voucher for deducting tax money.