一道SAT OC 语法
问题描述：
一道SAT OC 语法
long thought of as quiet, stuffy place where people just borrowed books, libraries( have been changing )their images dramatically over the last few years.
问下,前面是thought,为什么这不用had been changing,而用have been changing?句子时态不是要保持一致么.
答
这前面不是过去是,是being thought of as quiet,...作状语,长期以来被认为是 .,