1:铁路业主们不愿意冒险,于是他们雇佣了很多猎人向轨道沿线的美洲野牛（bison)疯狂射击.（take a chance)
The railway owners never try to take a chance so that the employ hunters to shoot the American bisons along the railway.
2:美洲野牛就在它们倒下的地方慢慢腐烂.（rot)
The bisons rotted where they fell down.
3：在被追逐和猎杀近90年后,美洲野牛最终得以安宁.（leave alone)
Left alone being chased and hunted for nearly 90 years,the American bisons finally get the peaceful life.
By the way,poor的名词形式是什么?（这句不是翻译）
poor的名词形式是poverty