Jeffrey Zibelman was a student in my high school graduating class at The Central High School of Philadelphia, 230th class (1971). We were in the same graduating class at The Pennsylvania State University (May 1975).
In high school, to the best of my recollection, we were in one class together: 12th-grade English, taught by Mr. Chester Plummer.
I remember that Zibelman sat at the back of the class. He was a compulsive reader, and read his personal books throughout class. Indeed, Zibelman's only extracurricular activity in high school was library aide. From time to time Mr. Plummer would say, "Isn't that right, Zibelman?" And Zibelman would answer, "Yes, Mr. Plummer."
Jeffrey Zibelman is on the top row, second from the left.