OG10-144

144. Efforts to equalize the funds available to school districts,
a major goal of education reformers and many states in the 1970's, has not
significantly reduced the gaps existing between the richest and poorest
districts.

(A)  has
not significantly reduced the gaps existing

(B)  has not been significant in reducing the gap that exists

(C)  has not made a significant reduction in the gap that exists

(D)  have
not significantly reduced the gap that
            exists

(E)   have not been significant in a reduction of the
            gaps existing

有两个问题，首先独立主格似乎只能在句首或句尾。另外不能因为没有分词儿判断不是独立主格，n+n;n+v-ed/v-ing;n+prep idiom;n+adj.都可以做独立主格。

至于这个a major goal....的成分，我认为它是一个概括性同为结构，对前面的解释对象进行概括。

呵呵，A兄我可不是LZ你才是楼主呢~

好了，言归正传，正是由于我说的两点原因，所以我说它肯定不是独立主格..

我的意见是这个名词短语是同位语结构，且是同位语从句中的概括性同位语从句，对前面的短语进行解释..efforts...

这种形式还是很常见的，A兄可以去查查，类似的有 a goal... /a program....etc。。也叫具体化同位语结构..应该有印象了吧。在这里我觉得这是最合语法结构，和逻辑的，不知A兄意见如何？

额。。把具体化和概括性同位从混淆了。具体化同位结构是对抽象名词解释~谢谢wentaow2008。概括性同位从是将前面的解释对象尽行概括。不能混为一谈。

确实，正如楼主所说同位从结构通常都是n+that。。但是对于非限制性同位从，有一种形式是用逗号隔开的~所以我坚持此句位非限制性德的概括性同位语从句~

问题应该解决了，这里是名词（词组）做同位语

example：

Anna, my best friend, was here last night.
Paul Jones, the distinguished art critic, died in his sleep last night

这里是efforts，goal 同位。同位对单复一致没有要求。

参考资料：http://www.scutde.net/Courses/course_1/Grammer1/nccegram_20apposition.htm

先前是把问题复杂了。看来有时还是想简单点。