After World War II, there were two things that, I think, contributed to the huge housing boom at that time.

第二次世界大战后,我认为,那时房地产的巨大繁荣主要归结于两件事

耶鲁公开课 - 金融市场课程节选

That's the main thing that they observed, but there's a second thing.

这是他们观察到得主要现象，但是第二件事。

麻省理工公开课 - 固态化学导论课程节选