Oh, yes, I'd also like some airmail stamps.

哦，好的，我也要一些航空邮票。

Yes. I'd like five airmail stamps.

对啦，我要买5枚航空邮票。

Would you like to send it by airmail or sea mail?

你要寄航空还是海运？

The postage for airmail is greater than that for regular mail.

航空的邮资较平。

I want to send this letter to the US by airmail.

我要把这封航空寄到美国。

I'd been sending letters by airmail to my daughter in the US once a week, but, suddenly, it was too expensive.

我一直在通过航空邮件给我在美国的女儿写，每星期一封，可是航空邮件突然涨价了。

I suggest you choose SAL. The cost of SAL is between sea mail and airmail; the shipping time period is also between sea mail and airmail.

我建议您采用空运水陆路方式。这种运输方式的费用和所需要的时间均介于海运和空运之间。

If the money was sent by cable, it would have taken about one or two days. But if it was sent by airmail, it would take at least one week.

如果是电汇，只需一两天。但是如果是航空邮递，至少需要一个星期。