Jack describe his father, who a brave boy many years ago, as a strong-willed man.
A. would be
B. would have been
C. must be
D. must have been
网友回答
A. would be
B. would have been
C. must be
(答案→)D. must have been
解析：考查情态动词表推测。因为是对过去事实的推测，要用情态动词+完成时态，排除A,C；根据as a strong-willed man.作为一个意志坚强的人，可知他许多年前肯定是一个勇敢的男孩。所以选D，表示肯定……。