Because mankind has lived through an earlier transformation in its communications environment, brought about by the invention of printing by movable type.
由于人类在通信环境经历了从较早的转变，是由活字印刷的发明带来的。
2
Imagine that the net represents a similar kind of transformation in our communications environment to that wrought by printing.
试想，互联网正在像印刷术一样变革我们的通信环境。
3
We often talk about inventions like the printing press and the television - by simply making communication more efficient, they led to a complete transformation of many important parts of society.