主谓一致的问题

sunlight841206

《白勇GMAT语法全解》中第三章：主谓一致
物质名词(如equipment, stone, eitrus, iron, milk, dioxin) + verb(单数);

但是该书中说  many of dioxins are .... 也正确。

这应该如何理解，难道many of dioxins的核心词是many?

SS2010

dioxin [c,u]

sunlight841206

多谢，我用的是 在线金山词霸！
太白痴了，自己~~~

SS2010

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