With the introduction of the computer , libraries today are quite different from _they were

Question

in the past. 分析句子成分 为什么用what 而不用 which

Answer 1

句子偏重于讲图书馆今时不同往日，比较的对象是以前的图书馆，所以用what指代之前的图书馆。which偏重于多选一，而这里不存在选择。

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