What joke was played in the process of information transmission?

The student wrote: "I was walking on the road when suddenly a pile of cow dung appeared on the road. I was shocked." After reading it, the teacher approved: "massive, massive." 2. The student wrote in the composition: "My mother is a middle-aged woman in her thirties." The teacher criticized under the word "middle age": "redundant." Then let the students copy it again. After the students copied it once, this sentence became. ...