17.　An attempt to ratify the Equal Rights Amendment, begun almost two decades ago, has been unsuccessful despite efforts by many important groups, including the National Organization for Women.

答案A

提问：

begun过去分词作状语，表示被动。记忆中begin没有被动的。为什么这里可以？

还是不很明白:

an attempt began almost 2 decades ago. 

an attempt was begun almost 2 decades ago.

本人觉得主动很顺, 反而被动, 怪怪的, 被开始吗?.....

请教高手指点.