The speaker mentioned many examples people lived through hard times and succeeded at last．
A. which
B. whose
C. when
D. where
网友回答
A. which
B. whose
C. when
(答案→)D. where
解析：句意:发言人提到了许多例子人们经历了艰苦的岁月而最后终于取得了成功。这里是定语从句，先行词是many examples，where在从句中作状语，故选D。