Question

a whose b his c whom d which 为什么不是whom 不是在从句中做主语成分吗代替his headteacher

he expressed his gratitude to his headteacher ,without ____help he wouldn't have made such great progress in his studies

Answer 1

A whose
后面的非限制性定语从句中，help是名词 帮助，名词前用 whose。
没有他的帮助，他不会取得如此大的进步。
从句中已经有主语了: he。
without whose help 是从句中的条件状语。

追问

whom 不能做宾语吗 干嘛非的中whose 呀

追答

without ____help he wouldn't have made such great progress in his studies.
这个句子我给你分析下：
he 主语
wouldn't have made 谓语
such great 定语 修饰 progress 宾语
in his studies 状语
最前面的 without (whose) help 条件状语