After 80 friends, the basic difference is not big. At that time, we used the People's Education Edition. So there is a popular article recently, which is nostalgia. See which texts and illustrations you remember. But by 1990, textbooks had gradually changed. In addition to the changes in cover illustrations and layout, the frequency of text updates has also accelerated. Of course, this is also relative to what I said before. Just change the text every two or three years. Most articles are familiar to us.