og13 80 求nn解答~

qsjvicky

80. 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


想问一下，如果b选项把muchg改成many：many of the currently uncontrolled dioxins that North Americans are exposed to come,对嘛？现在和e选项的差别就在于that...to和to which了？一定要用to which结构而不能用that...exposed to结构吗？