高一英语（改成同位语从句）He suggested that we should take the train from

His suggestion that we should take the train from west to east across Canada , sounds very exciting.
同位语从句必须是that引导,而且不能省略,而且必须是that引导的句子.his suggestion意为 “他的建议”,而他的建议就是we should ~~~across Canada,同位语从句也就是说,his suggestion 与we should ~~~across Canada说的就是同一个东西,而that后的从句是对his suggestion 的同一表述.
只有少数词有这种用法,你只需把这些词记住,记住句型,套用就可以了,idea,plan,fact,theory,promise,hope,news,doubt,truth,information,suggestion,question, thought,belief,conclusion.

His suggestion,taking the train from west to east across Canada,sounds very exciting

His suggestion that we should take the train from west to east across Canada sounds very exciting.
同位语从句就是名词+that结构, that后面接一个完整句(单独拿出来是一个完整的句子)
就这样就行了.
然后同位语从句是一个从句, 主句变成了his suggestion, ...