In contrast, the major axis of Eurasia is east–west.

相比之下，欧亚大陆轴线是东西向。

That is, the major axis of the Americas is north–south.

也就是，轴线是南北向。

It lacks the severe ecological barriers transecting the major axes of the Americas and Africa.

它没有横贯和非轴线严重生态障碍。

Its east–west major axis permitted many inventions adopted in one part of Eurasia to spread relatively rapidly to societies at similar latitudes and climates elsewhere in Eurasia.

它东西向轴使得欧亚大陆某一地区采用许多发明能够相对较快地传播到欧亚大陆其他地区类似纬度和气候社会。