Don't forget to stick a stamp on an envelope before you put it into the mail-box.
Don't forget to stick a stamp on an envelope before you put it into the mail-box.
把信投进信箱前别忘了在信封上贴上邮票。
Don't forget to stick a stamp on an envelope before you put it into the mail-box.
把信投进信箱前别忘了在信封上贴上邮票。