34. A report by the American Academy for the Advance­ment of Science has concluded that much of the currently uncontrolled dioxins to which North Ameri­cans are exposed comes from the incineration of wastes.
(A)  much of the currently uncontrolled dioxins to which North Americans are exposed comes
(B)  much of the currently uncontrolled dioxins that North Americans are exposed to come
(C)  much of the dioxins that are currently uncon­trolled and that North Americans are exposed to comes
(D)  many of the dioxins that are currently uncontrolled and North Americans are exposed to come
(E)  many of the currently uncontrolled dioxins to which North Americans are exposed come
 
 
1．单复数一致：（一级排除 A,B,C )
dioxins 为可数复数名词应用many, come
主谓单复数一致：
修饰词的单复数一致： much + 不可数名词 ； many + 可数名词

2．简洁/平行结构：二级排除 D )
n. + that/ whose /which be + adj. 没有 adj. + n. 简洁。
currently uncontrolled dioxins / dioxins that are currently uncontrolled
D requires that before North Americans, to be grammatically complete.
dioxins to which North Americans are exposed / many of the dioxins ……  and North Americans are exposed to 改变了句子意思和逻辑关系。
 
3．修饰： 修饰顺序： a report by … for ……

4．平行结构： 逻辑意思决定了分句/主句的平行。改变原句的层次会改变句子意思。