Brave and strong, the activists talked to the workers outside the factory.

理解(1)修饰后面谓语动词talked to，相当于其副词放在句子作状语的语法功能。

The activists talked to the workers bravely and strongly outside the factory

理解(2)相当于定语从句，修饰后面句子主语the activists

The activists,who are bravel strong, talked to workers outside the factory.

Bravely and strongly, the activists talked to workers outside the factory.

解答如下

brave and strong形容词作状语，用来修饰后面句子谓语动词,有时候好相当于非限制性定语从句，用来修饰后面句子主语。

bravely and strongly 副词作状语，是用来修饰后面整个句子内容，作评论性状语。

Nervous, she tore open the letter.

Nervously, she tore open the letter.

用法同上

Helpless,we watched the house being destroyed before our eyes．

Helplessly,we watched the house being destroyed before our eyes．

用法同上

以上解答观点仅供参考！