第23题: [单项选择]He didn't ______ and so he failed the examination. A. work enough hard B. hard work enough C. hard enough work D. work hard enough 参考答案:D 答案解析:本题为词序搭配问题。enough修饰名词时可放在所修饰的名词前面也可放在所修饰的名词后面,而当enough修饰形容词或副词时只能放在所修饰的词后面。本句大意为:他学习得不够努力所以考试失败。