1993～ 1 996年作者研究了豆田 1 6种可控因素对夏大豆病虫害、天敌和产量的综合效应。根据既控病虫增产又保护生态的原则 ,综合评价......

In China, with the development of projects such as ＂electricity transmission from the West to the East＂ and ＂power exchange......