单选题 ______ finish his homework, he would have come to class.
A. If Mike could B. Were Mike able to
C. Would Mike be able to D. If Mike had been able to

【正确答案】 D

【答案解析】[解析] 本题测试的是虚拟语气过去时，又称非真实条件句过去时，其中的条件状语从句用过去完成时，主句谓语用would/could/might have+过去分词。由于本句用了would have come，就应选含有过去完成时的条件句。相反，如果题中给出了含有过去完成时的条件句，就应选含有would/could/might+完成式表示结果的主句。