I was at a party a few weeks ago which was more exciting than I had expected it to be.这里ago

问题描述:

I was at a party a few weeks ago which was more exciting than I had expected it to be.这里ago
后面为什么用which,最后的it后面为什么用to be

which指代the party [a few weeks ago 是时间状语]
expect something to be...期望某事怎么样 固定用法