savings stamp

例句：

1. 1. She bought a savings stamp for her son's college fund.
   她给儿子的大学基金买了一张储蓄邮票。
2. 2.The post office sells savings stamps at the end of each month.
   邮局每个月末出售储蓄邮票。
3. 3. He used his savings stamp to buy a new car.
   他用他的储蓄邮票买了一辆新车。