单选题 John is very diligent, but his pay isn't sufficient enough for his work.
A. good B. much C. legal D. sound

【正确答案】 A

【答案解析】[解析] enough是程度副词，它一般放在它所修饰的形容词或副词之后；例：good enough，warm enough等等；因此A为答案。