同学你好，该知识点来自沪江网校《英语零基础直达大学六级【8月班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好~
这里嵌套了一个强调句it was…that
特殊疑问句形式的强调句可视为对陈述句强调中的被强调成分提问得来，如对
It was in 1985 that he was born 这一句中的in 1985提问，
即得到When was it that he was born?
这里因为how在前（这里强调how），就相当于how was it that he was still alive，因为是宾语从句，所以变成了陈述语序，how it was that he was still alive
去掉it was…that，也就是Hans explained how he was still alive.

祝同学学习进步~