【题目】---She looks very happy. She ______ have passed the exam.
---I guess so. It’s not difficult after all.
A. would B. should
C. must D. ought to
在线课程【答案】C
【解析】
试题分析：C考查情态动词表推测。Must用于肯定句中，表肯定的推测，译为“一定，肯定”；would表推测，译为“大概”；should=ought to表推测，译为“应该”；句意：——她看起来非常高兴。肯定是过了那场考试。——我猜也是。毕竟那不是很难。故选C