| 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
帮忙讲下lack的用法吧，我已经知道的正确形式有a lack of lack sth，不知道对不对。
还有这个题里E选项lacking 是形容词吗。
除此之外，lack还有别的用法吗，或者什么常见的错误用法 | 
