问题补充：
Jack described his father, who a brave boy many years ago, as a strongwilled man.
A. would be
B. would have been
C. must have been
D. must be
答案：
A. would be
B. would have been
(答案→)C. must have been
D. must be
解析：情态动词题。Must have done 对过去的推测。 杰克说他的父亲是意志坚强的人，多年前他肯定是勇敢的孩子。根据语境选C
