最長的單詞怎么寫

　　The Yangtze River is the longest river in China and the third longest in the world.

　　揚子江是中國最長的河流,也是世界第三長河。

　　The longest ditch in the world, as it was called, 300-and-some-odd miles out to Buffalo.

　　它被稱為世界最長的運河，距布法羅城300多公里。

　　It's one of the longest and deepest limestone caves not just in the country but in the world.

　　它不僅是美國最長最深的石灰巖洞穴之一，也是世界上最長最深的石灰巖洞穴之一。

　　Among them the Yangtze River is the longest one and the second longest one is the Yellow River.

　　其中最長的是長江，第二長的是黃河。