星级典句:
第一句: Can I buy some stamps and envelopes here?
这儿卖邮票和信封吗？
A: Can I buy some stamps and envelopes here?
这儿卖邮票和信封吗？
B: Yes. How many stamps and envelopes do you want to buy?
是的。您要买几张邮票和几个信封？

第二句: Could you tell me where I can get the registered envelope and some stamps?
请告诉我在哪儿能买到挂号信封和邮票？
A: Excuse me. Could you tell me where I can get the registered envelope and some stamps?
请问我在哪儿能买到挂号信封和邮票？
B: At that counter.
在哪个柜台。

其他表达法:
IThe envelpe was firmly sealed.
这个信封封的很严实。
Please address the envelope before mailing the letter.
寄信前，请在信封上写上地址。