(C) and don’t know 皆須改
They walked east instead of south and didn’t know their mistake.
分詞構句:(1)主詞相同的話,要省略一個主詞。(2)在被省略主詞後方的動詞,要改成分詞,也就是 Ving 或 V-ed。(3)去掉連接詞(and, so, if 等等)因此原句為They walked east instead of south,and they didn't know their mistake.
28. They walked east instead of south, _..-阿摩線上測驗