答案：C

题目分析：考查非谓语动词，A .making up of由…制作；C. consisting of由…组成，句子意思“由80个学生组成的班级很难管理”

点评：非谓语动词是个难点，是高考常考内容之一，要求学生知道非谓语的用法

即学即练：________ of her happy childhood by the song, Grandma sang along with it in a soft voice.

A. Reminded     B. Reminding    C. Having reminded      D.Being reminding

选A