When we started with the entire class, I showed the children how to bind the book by hand.

当我们开始整堂课的时候，我教孩子们如何手工装订书本。

youdao

But a book... a book is cheap to print and bind.

但是书就不一样了…印刷和装订一本书很便宜。

youdao

People had to copy each page by hand. Then they had to bind the pages together to make a book.

人们不得不手工复制每一页。然后他们必须绑定页面，在一起制作一本书。

youdao

When we started with the entire class, I showed the children how to bind the book by hand.

这门课最开始的时候，我向孩子们展示了如何把书用绳子缝起来。

麻省理工公开课 - 媒体、教育、市场课程节选