复数： Americans

The american effort faced other problems too .

美国人同样在努力面对其他难题。

Distinctions between aurochs and american bisons are not substantial .

欧洲野牛和美洲野牛的区别不明显。

And the american economy is tottering .

美国的经济正在蹒跚前行。

The american economy is dynamic .

美国经济是动态的。

Central american governments have been doing more themselves .

中美洲各政府自己列了更多算。