一) 中国的垄作耕法有着悠久的历史,它大约创始于西周,初步发展于春秋战国,大发展于秦汉至隋唐五代,到宋元明清时代达到成熟阶段,(二) 并在科学技术上取得了光辉的成就... 郭文韬 - 《中国农史》 被引量: 58发表: 1992年 粉垄技术护卫粮食,生态安全 ·盖茨誉为最伟大的发明之一的,5500年前发明的耕作工具"犁头...
Chinese iron ore import prices jumped by $2/t over the day on more purchases in the overseas market and a newround of restrictions in Tangshan. Low stocks at mills are likely to support market quotes in the near future.Australian iron ore fines 62% Fe jumped by $2/t, reaching $72/t...