[求助]关于-OG-103中词性的请教

103. Students in the metropolitan school district lack math skills to such a large degree as to make it difficult to absorb them into a city economy becoming ever more dependent on information-based industries.

(A) lack math skills to such a large degree as to make it difficult to absorb them into a city economy becoming

(B) lack math skills to a large enough degree that they will be difficult to absorb into a city’s economy that becomes

(C) lack of math skills is so large as to be difficult to absorb them into a city’s economy that becomes

(D) are lacking so much in math skills as to be difficult to absorb into a city’s economy becoming（E）

(E) are so lacking in math skills that it will be difficult to absorb them into a city economy becoming

C is ungrammatical because it uses lack as a noun rather than as a verb:，解释上说LACK 本选 项是作了一个名词，那么我怎么能自己在看题时就认出这个LACK是名词而不是动词呢，我就选 了C这个选 项，可是错误的原因就在于我认为LACK是动词

谢谢

lukrenee,经你这么一说，有种恍然大悟的感觉，

谢谢