美国农业发展 英语.ppt

American Agriculture ;;;Importance;;Many big farms hire temporary workers only for a specific chore—such as picking crops. Many of these seasonal workers travel from farm to farm, staying only until the crops are picked. They are known as migrant workers. ;Nature’s bounty Effective use of machines Big surprise :one farmer=75 people;Brightness: the richness of US agriculture is mainly due to the vastness of the nation and the generosity of nature Darkness: low profit caused by crop trading surpluses Environment damage with the large use of artificial fertilizers and toxic chemicals;Manufacturing Industry;The US has large manufacturing ,like Computer and eletronic products ;chemicals,fOOd ,tobacco and berverages;and petroleum products . They acccont for about 51％ of the US Manufacturing GDP.;;The Boeing company;The Boeing company