核心问题
Who are you that you should be so rude to us?
that 从句是什么类型的从句?
词典解答
that从句是结果状语从句。句意是：“你是谁，竟敢对我们如此粗鲁？”这种句型还可以扩展到：What...that...should,Where...that...should,How many...that...should。见so...that,what...that。
who(m)...to/to whom 见 about , what...on/on what, with whom/whom...with who else's/whose else 见 else