| A.the stamps may lose color |
| B.you may not find them anywhere |
| C.the stamps may be out of date |
| D.you do not know how many are left |
| A.buy photo stamps at a very low price |
| B.send their international mails for free |
| C.design their own photo stamps |
| D.have their letters delivered faster than before |
| A.He thinks they are a great idea. |
| B.He is afraid they may cause trouble. |
| C.He thinks they save a lot of money. |
| D.He thinks they are as good as the traditional ones. |