Jim was not______ his maths teacher’s explanation of the problem, for he was still puzzled about it.
A、aware of
B、positive about
C、impressed by
D、content with
【正确答案】：D
【题目解析】：aware of意识到。positive about 对…积极。impressed by 对…印象深刻。content with 满足于…。句意：吉姆对数学老师的讲解印象并不深刻，因为他还很困惑。
