单选题 He had studied hard , he would have been able to pass the exam.
【正确答案】 C
【答案解析】[解析] 本题考查虚拟语气的用法。如果虚拟从句中含有助动词、情态动词、动词be或have，则可把if省略，把上类动词提到主语之前，使用倒装语序。