envelope cartridge

例句：

1. 1. Theenvelope was addressed to my mother'shouse.
   信封上写着寄给我母亲的地址。
2. 2.He carefully sealed the envelope with a redribbon.
   他用红丝带仔细地封好了信封。
3. 3. The package inside the envelope isfor sale.
   信封里的包裹是出售的。