VOA慢速英语:States Put Pressure on Public Unions

1.Workers in Wisconsin, and now some other states, have been protesting efforts to limit the negotiating power of government employees.

to limit不定式做后置定语，修饰efforts。have been protesting是现在完成进行时。

2.They are barred from striking.

bar from禁止(接近〔做〕…)

例句：The members voted to bar women from the club.
      会员表决不让妇女加入该俱乐部。

      After the member was caught cheating, he was barred from the club.
      那会员行骗被抓后, 被开除会籍。

3.Wisconsin was the first in the nation to establish the right of public employees to bargain collectively, and it's a real shock to a lot of people that these rights would be taken away.

the first to do第一个做某事的....it's a real shock中的it是形式主语，真正的主语是that引导的从句。

4.Collective bargaining rights differ from state to state.

differ from与…不同

例句：She differs from her sister in the color of her eyes.
      她与她姐姐眼睛的颜色不同。

      She differs from her brother in character.
      她与她哥哥性格不同。