OG12-80

xiaotangyu

80. A  report by the American Academy for the Advancement of Science has concluded that much of the current uncontrolled dioxins to which North Americans are exposed comes from the incineration wastes.
正确答案 (E)many of the currently uncontrolled dioxins to which North Americans are exposed come
谁能帮我回答一下，这里为什么要用to which? 它指定是什么？

zonderss

dioxins which North Americans are exposed to comes from the incineration wastes.
等于
dioxins to which North Americans are exposed comes from the incineration wastes.
which是修饰dioxins

xiaotangyu

仔细想了想 反而晕了

等下，我忽然觉得to which中的 which,不是指be exposed to，而是指the currently uncontrolled dioxins
想想好像又不对，有谁能详细分析下句子啊？

James

这里to which实际上是引导了一个定语从句
一般来说 对于限定定语从句 而 先行词在定语从句中作介词宾语的话
那么需要把介词提前 并且用which引导这个定语从句

所以上面 Nicole说的是对的
doxins在后面那个定语从句中实际上是be exposed to的宾语 这个to是一个介词
所以需要把to 提前 然后用which引导
就变成了我们所看到的 to which North Americans are exposed 这个定语从句
这里 不能用that引导 而必须用which引导 也是因为介词存在的原因

希望上面的解释能够帮助你

NicoleYu

这样把句子的顺序变一下楼主就明白了吧：）

North Americans are exposed to the uncontrolled dioxins

xiaotangyu

哦～～～～
对对对，这是个被动语态，秀逗了！
如果我改成many of the currently uncontrolled dioxins that are exposed by north americans come可以吗？
我觉得这样更清楚明了

huanmingloj

be exposed to

stone021

to which指North Americans