第26题: [单项选择]John's score on the test is the highest in the class; he ______ last night. A. must study B. should have studied C. must have studied D. is sure to study 参考答案:C 答案解析:[解析] 根据题干可知,后一分句是对过去,情况的推测,可直接排除[A]和[D]。[B] should have studied表示过去本应该学习而实际上并未这样做,故答案为[C]。