Question

4. He was such a secure man; I never        him do anything without a very good reason,

   A. understood   B. realized

   C. learned   D. knew

Answer 1

4. D know意为"了解，知道"，此题侧重考查动词的用法。在这组动词中，只有know用于过去及完成时态中时,其后用作宾补的不定式可以省略to。