请问d项中的are起什么作用？为什么有个are?

jennyguoguo

Companies in the US are providing job training for nearly 8million people,
about the equivalent of those enrolled in the nation’s four-year colleges
and universities.
A.    …
B.    equal to those who are enrolled in
C.    as many as the enrollment of
D.    as many as are enrolled in

key: d        
请问d项中的are起什么作用？为什么有个are?

[此贴子已经被作者于2003-7-12 9:58:32编辑过]

tocean0222

are前面省略了those；

ququshethy

以下是引用tocean0222在2003-7-13 1:39:00的发言：
are前面省略了those；

这里不存在省略的问题吧。as已经代表这个含义了。加上those反倒应该是错的吧。

rogersun

here, 'many' is the subject, 'are enrolled' is the verb in passive tense

木川

省略了those，是比较中的主语省略。