单选题 If I ______ the exam, he would be astonished.
A. did pass B. pass C. were to pass D. had passed

【正确答案】 D
【答案解析】[解析] 这句话是错综虚拟语气句，从句为与过去事实相反的虚拟语气，用had done。主句为与现在事实相反的虚拟语气，用would/should/could+动词原形。