关于主谓一致

rainbow1013

我在做句子改错题时遇到这么一个题目,实在是搞不懂,请高手指点下.谢谢!

The newly elected baseball commisioner has asked a federal arbitrator to mediate negotiations between representives of the umpire's union, which has thretened to go on strike, and the layers representing major league franchise owners.

红线是划线部分并且是正确的选项.我不明白为什么representives of the umpire's union 的谓语是has呢?

 

AlienX

which是指代union

southnorth

union which has thretened 好像不符合逻辑吧。

AlienX

hmm...why?

southnorth

union不是人或动物，怎么可以用主动的呢？