一、简介许多年来,人们寄信所使用的信封为传统型折叠式信封。随着当代高科技录音、录像、打字、录字、胶卷、软盘等新技术新产品的出现,人们交流思想感情、传递信息的手段趋于多样化、快速化,一盘录音录像带、一盒录字软盘,能代替千言万语或数百万字的文 I. Introduction For many years, the envelopes used by people to send letters are traditional type of folded envelopes. With the advent of new hi-tech new technologies and products such as recording, video recording, typing, recording, filming and floppy disks, people are exchanging thoughts and feelings and diversifying and expediting the means of transmitting information. A video tape, a box of records Word floppy disk, can replace a thousand words or millions of words of text