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来源：雅诚德英语网
Sowing seeds about April 20, the coefficient of leaf area assort with the productivity of single plant, the yield of maize is tallest, and can resist and avoid the drought;
谷雨节前后播种，叶面积系数与单株生产力协调一致达最佳，玉米产量最高，既能抗夏旱又能避伏旱；