问题补充：
All the books are not useful. Which of the following has the same meaning as this sentence?
A. All the books are useful
B. Neither of the books is useful
C. Not all the books are useful
D. None of the books are useful
答案：
A. All the books are useful
B. Neither of the books is useful
(答案→)C. Not all the books are useful
D. None of the books are useful
解析：考查部分否定。否定词not与all, both, each, every等连用，不管not的位置在前面还是在后面，都是部分倒装。使用All the books are not useful.= Not all the books are useful；意为：不是所有的书都有用。故C正确。
