[解析] 细节理解题。由第一段最后一句话“One of the reasons that made it cool for him not to care was the power of his peer group.”可知受同龄人的影响，年轻人把不在乎学习看成是很酷的一件事情。
[答案] C
7. What seems to have a bad effect on students like Tom?
A. Peer groups.
B. A special unit.
C. The student judges.
