关于 to which 的一点疑问

题目

关于 to which 的一点疑问
In fact, parts of it apparently were extremely difficult to sequence because they were so different from other mammalian genomes, to which we often compare sequences in order to align them and put the sequence together.
我的问题是这里的 to which 后面的 which 是指代前面哪个名词
我读的时候是把which 替换成句子最大的主语,但这里好像行不通,望高手帮我解疑
另外 to which= where 吗?
能否把这个句子重新排下序呢

答案

to which不等于where.
to 和 which 是分开的,这点你要理解.
其实在which 前面加to,with,或者其他介词,都是因为which后面的动词.这里的话,就是compare
所以理解起来是,compare to which的意思