请帮我解释一下一下这个句子中为什么用“in that most tedious of subjects",是个什么语法?

题目

请帮我解释一下一下这个句子中为什么用“in that most tedious of subjects",是个什么语法?
When our class was assigned to Mr.Fleagle for third-year English I anticipated another cheerless year in that most tedious of subjects.

答案

说这句话的人表达一种非常无奈和失望的语气.
in that most tedious of subjects,可以解释为在那样一个最无聊的科目上.that解释为“那样的”,不做指示代词,只是表达一种抱怨的语气.
Wish it helps =]