【题目】曾经有段时间我非常厌倦学习。
I got study.

【答案】There；was；a；time；when；tired；of
【解析】句型：There was a time when……曾经有一段时间……，此处包含了一个when引导的定语从句；be/get tired of对……感到厌烦。所以答案是There was a time when ... tired of。