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hiiamjo

1. Doctors still know little about how the Listeria bacterium is spread and why the disease it causes, listeriosis, afflicts some people in a contaminated area though it spares many others.

(A) though it spares

(B) where it spares

(C) despite sparing

(D) when sparing（E）

(E) while sparing

when 和while在用法上有什么区别？

vagrant

when 接一般现在或一般过去时比较多；while 接进行时态比较多