回想起来，我能看出我们哪里出了问题。

___Looking ___back, I can see where we went wrong.

当我回想起我的学生时代，我有很多美好的回忆。

When I ___look ___back on my school days, I have many fond memories.

人们常常怀旧地回想起他们的青春年华。

People often ___look ___back on their youth with nostalgia.