what we used to think was impossible does now seem possible

问题描述:

what we used to think was impossible does now seem possible
what we used to think 做主语, was impossible 是系表结构,那后面的呢?

what we used to think was impossible 是主语从句,也就是说整个相当于主语,后面does是谓语,(what)now seem possibles 是宾语从句