大全249-补充250-T175

175/DQ249.  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 sparest在未划线部分显示其应该指代Listeria bacterium，disease指代listeriosis，afflicts的主语是listeriosis；itz在划线部分逻辑上指代listeriosis，与未划线部分的it指代形成冲突，错。

(B) where it spares

(C) despite sparing

(D) when sparing（E）

(E) while sparingwhile sparing many others是表伴随，与前面的afflicts some people形成对比，意思是说：在污染地区，这种病使某些人深受其害，而让许多其他人却不受影响。

答案没有问题

我的问题是listeriosis, afflicts some people in a contaminated area though it spares many others.是作什么成分在句中

如果作疾病的同位语要用

listeriosis that afflicts some people in a contaminated area though it spares many others.

谢谢

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.

我看listeroisis 是disease 的同位语，整个句子结构是：

Doctor know little about how...and why the disease...,listerriosis, afflicts some people....

谢谢sofarsgood
明白了

不客气。