A：Would you please weigh this letter to see what the postage is?
      麻烦您称一下这封信，看看需要多少邮资，好吗？

B：Do you want to send it by ordinary or registered mail?
      您是要寄普通信还是挂号信？

A：By ordinary air mail, please.
      请给我寄普通航空信。

B：Anything of value in it?
      里面有什么值钱的东西吗？

A：A postal order for four hundred dollars.
      一张400 美元的邮政汇票。

B：In that case, you’d better have it registered.
      既然那样，您最好寄挂号信。

ordinary的反义词

A：Will I be informed when my friend gets the letter?
      当我朋友收到这封信后，我会被通知吗？

B：Yes, when your friend gets it, he’ll sign a receipt, which will be sent to you by mail. Then you can be sure it’s been received.
      是的，当您的朋友收到信后，他将签一张收据，这张收据会寄给您，您就可以确定他收到了。

A：All right, I’ll have it registered, then.
      好，那我就寄挂号信。

1. 平常的；普通的；一般的；平凡的
    Ordinary people or things are normal and not special or different in any way.

    e.g. I strongly suspect that most ordinary people would agree with me...
           我坚定地认为绝大部分老百姓会赞同我的观点。
    e.g. It has 25 calories less than ordinary ice cream...
           它所含热量比普通的冰激凌少了25卡路里。

2. 平庸的；平淡无奇的
    If you describe someone or something as ordinary, you mean they are not special or interesting in any way and may be rather dull.

    e.g. I'm just a very ordinary, boring normal guy...
           我只是一个颇为平庸无趣的普通人。
    e.g. Your life since then must have seemed very ordinary.
           你的生活从那时起一定非常平淡无奇。

3. 不寻常的；非凡的；特殊的
    Something that is out of the ordinary is unusual or different.

    e.g. The boy's knowledge was out of the ordinary...
           这个男孩懂得的知识非比寻常。
    e.g. I've noticed nothing out of the ordinary.
           我没注意到什么特别之处。