At that very moment, I thought Liang Bo the winner of The Voice of China, though I was not 100% percent sure.
A. might be
B. must be
C. could be
D. might not be
网友回答
A. might be
(答案→)B. must be
C. could be
D. might not be
解析：考查情态动词辨析。Might也许；must一定，必须；could可能;句意：在那时，我认为梁博一定是冠军，尽管我不是百分百的肯定。根据句意说明使用must。故B正确。