There are trees on( ) ( )of the road.=There are trees on both sides of the road.括号里为什么填写either side

问题描述:

There are trees on( ) ( )of the road.=There are trees on both sides of the road.
括号里为什么填写either side

either of 表示两者中的任意一个,因为road道路只有两个边,所以只能用either或者both表示两边,either后跟单数side,both后跟复数sides.类似的还有either side of the river,both sides of the river.