After _seemed like hours,the big fire was finally brought under control.

问题描述:

After _seemed like hours,the big fire was finally brought under control.
A.which B.it C.what D.that
正确答案是C,不懂为什么,我自己选的是B

好问题.
简单的解释是,在这个情况下,what 代表 "that which" 或 "something which" 的意思.用 what 而不用其他两个词语比较简洁.after that which seemed like hours?这个that是fire吗