The man _______ be a doctor in this hospital, but I’m not sure.
句意：这个男人可能是这个医院里的医生，但是我不确定。
考查情态动词。A. must必须，表示禁止；B. would将；C. can能、可以；D. might可能，表示没有把握的推测。根据题干中but I’m not sure.可知是推测这个男人可能是这个医院里的医生，故答案选D。
The man _______ be a doctor in this hospital, but I’m not sure.
—Whose notebook is this?
—It ________ be Alan’s. It looks like his.
Mary ________ go to London next year but she is not sure.
