Question

when he was set free after twenty years in prison, he was amazed at the changes he found

请问这句话的意思，并分析这个句子。谢谢！

Answer 1

他在监狱呆了二十年，出狱后，他对周围的变化感到很惊奇。
when he was set free after twenty years in prison 是表示时间的从句；
was set free：被释放 in prison在监狱

he was amazed at the changes he found。是句子的主体部分。
was amazed at：对···感到惊奇。 he found修饰the changes

就是这样！！

Answer 2

当他坐了二十年牢被放时，他对他所发现的改变而感到吃惊。