Question

Jack described 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.
我最想问的是，为什么C 不可以是答案？

Answer 1

many years ago ，明显是对过去的推测。
所以 选D。
must be 是对现在的推测。故错

Answer 2

答案：D.
考点：本题考查情态动词推测用法。
解析：句意为“杰克把他的父亲描述为一个意志坚强的人，他的父亲多年前肯定很勇敢。”用must have been表示对过去事情的肯定推测。