OG 12 Q70 望NN指点

半阙

His studies of ice-polished rocks in his Alpine
homeland, far outside the range of present-day
glaciers, led Louis Agassiz in 1837 to propose the
concept of an age in which great ice sheets had
existed in now currently temperate areas.
(A) in which great ice sheets had existed in now
currently temperate areas
(B) in which great ice sheets existed in what are
now temperate areas
(C) when great ice sheets existed where there were
areas now temperate
(D) when great ice sheets had existed in current
temperate areas
(E) when great ice sheets existed in areas now that
are temperate


答案是B，我想问一下这里的in which great ice sheets existed in what are...  这两个in 不重复么？我觉得后面那个in 应该省略~~望NN指点~~

半阙

自己顶。。。