请教一个英语句子的语法结构Accurateclassificationiscomplicatedbytheunusualusetowhichsomeprotocolsareput.这句话中“towhich”以及它后面的句子在整句话中是什么成分啊,这个句子是什么样的一个语

Question

请教一个英语句子的语法结构
Accurate classification is complicated by the unusual use to which some protocols are put.这句话中“to which”以及它后面的句子在整句话中是什么成分啊,这个句子是什么样的一个语法结构.

Answer 1

Accurate classification is complicated by [the unusual use} {to which some protocols are put}
先行词 定语从句 .