单选题 If we had not followed the reform and opening up policy, we ______ such great achievements in our socialist construction.
【正确答案】 B
【答案解析】[解析] 从句子看,if从句的动词形式是had+done(followed),是对过去事实的虚拟,所以主句应用should/would/could/might+have done,且句子为否定句,正确答案为B。