xīn / wén / lǐ / huí / gù / zhè / duàn / lì / shǐ / shí / cháng / yòng / bái / yún / cāng / gǒu / lái / xíng / róng / shí / dài / de / biàn / huà

新闻里回顾这段历史时，常用白云苍狗来形容时代的变化。

When reviewing this period of history, the news often uses this idiom to describe changes over time.