问题
选择题
Mr. Bob, ______ as a manager for many years, found it hard to be an ordinary clerk again.
A．having worked
B．worked
C．to have worked
D．working
答案
A
题目分析：考查现在分词的完成式做状语：句意：做经理很多年后，鲍勃先生发现很难做一个普通的职员了。根据句意，鲍勃先生是先做经理，然后才发现做秘书难的，当状语的动作发生在主句的动作之前，用现在分词的完成式做状语，选A。
