He studies to pass the exam.A. hard enoughB. hardly enoughC. enough hardD. enough hardly

问题补充：

He studies to pass the exam.

A. hard enough

B. hardly enough

C. enough hard

D. enough hardly

答案：

(答案→)A. hard enough

B. hardly enough

C. enough hard

D. enough hardly

解析：考查hard和enough的用法。句意“他很努力地学习，为了提高考试。”hard既可作形容词“困难的，坚硬的”；也可作副词“努力地，猛烈地”。而hardly是副词“几乎不”，表示否定。排除B、D；enough修饰形容词和副词要放在他们后面，排除C。故选A。