And why only snakes? Cats, for instance, would be greatly helped; no running fights with large, fierce rats or tussles with grown rabbits -- just a bite and no more effort needed. In fact, it would be an assistance to all carnivores though it would be a two-edged weapon when they fought each other.
参考译文：为何只有蛇才有毒液呢？譬如说，假如猫有毒液，那对猫会大有帮助，它就不必再和又大又凶的老鼠边跑边博斗了，也不必再和大兔子扭斗了，只须咬一口，就不必再费大力气。因此，任何食肉动物有了毒液，都能从中获益。不过，当它们相互撕打时，毒液就成了利弊参半的武器，可以杀死他们，也可以被他们的毒液杀死。
问题：句中的fights和tussles 是名词还是动词？cats是它们的主语吗？
fights 和tussles 为复数名词， 可以理解为该句省略了主谓语，cats 可以是主语，即Cats would have no running fights with...。也可以理解为省略了There would be no running fights with...
