Packet level filtering

例句：

1. 1.The package arrived safely on time.
   包裹准时安全到达。
2. 2.The sender sent a package containing gifts for the recipient.
   发件人寄了一个包含礼物的包裹给收件人。
3. 3.The package was too heavy to be carried by one person.
   这个包裹太重了，一个人搬不动。