菜鸟问题：白勇语法4章18题，谢谢

:Although it claims to delve into political issues, television can be superficial, as when
                        the three major networks each broadcast exactly the same statement from a political candidate.

文中已经是正确答案，但是我对黑体的each不理解．　前面是three networks each是单数，后面的谓语broadcast为什么用复数形式。

谢谢赐教！

复数名词+each+动词复数

each of +复数名词+动词单数