Omnivore's Delimma(4th)

Corn plants' population explosion in places like Iowa is responsible for pushing out not only other plants but animals and then finally people too.

传统的农场经营多种农作物和饲养牛羊马鸡等牲畜，这种多样性不到能够维持农场的可持续发展，同样肥沃了土壤喂养了牲畜，并且还能保证农场不破产在任何一种农作物价格价格下跌的时候。随着机械化的到来和化肥发明，农场不在需要牛和马来耕地，机械化生产不需要太多的人数，而且鸡马牛羊的生长远远比不过饲养场里鸡马牛羊，化肥使得农民不在担心单种栽培使土地贫瘠。在加上杂交玉米种子的研发，玉米的产量大大的增加了。供大于求，玉米的价格大幅度下跌，导致大量的农民破产，最终受害的还是农民自己。

sentences and words:

Instead of eating exclusively from the sun,humanity now began  to  sip petroleum.

Haber's  story embodies  the paradoxes of science: the double edge to our  manipulations  of nature.

Corn prices were at an all-time high

even out:使平整，使均衡

make  a go of sth:使成功

nail down:明确，确定

hayday:全盛期

perturb:扰乱，打扰