The Changjiang River is one of the longest rivers in the world.

题目

The Changjiang River is one of the longest rivers in the world.
river为什么要加“S”呢,

答案

one of + the + 最高级 + 复数名词,表示“...其中之一”.
The Changjiang River is one of the longest rivers in the world.
翻译：长江是世界上最长的河流之一.