问题补充：
To help a friend solve the problem troubling him,.
A. a friend should be made known of his difficult situation
B. a man should be equipped with the kind of knowledge required
C. nothing is better than offering of knowledge required
D. keeping one’s promises is most important
答案：
A. a friend should be made known of his difficult situation
(答案→)B. a man should be equipped with the kind of knowledge required
C. nothing is better than offering of knowledge required
D. keeping one’s promises is most important
解析：考查不定式的用法，这里不定式做目的状语，不定式的逻辑主语应该和主句的逻辑主语一致，这题结合句意应该是a man，句意是：为了帮助朋友解决困扰他的问题，一个人应该具备需要的这种知识。选B。
