为什么这句话有语病?

问题描述:

为什么这句话有语病?
Six years later,when I won the first prize in National English Contest for College Students,and had acted as the president of a speech club for a year,I felt that my efforts had paid off to some extent.WORD在year下划了绿色曲线,错哪了?该怎么说?

改为:had been acting as .for a year.就对了.
因为这个是个持续的动作的.