BEFORE THAT, WHAT DID PEOPLE HAVE TO DO WHEN THEY GOT A LETTER

3) - TONG HOP KIEN THUC TIENG ANH THCS VA CAC BAI KIEM TRA THU
TONG HOP KIEN THUC TIENG ANH THCS VA CAC BAI KIEM TRA THU
3) Before that, what did people have to do when they got a letter?