The person I want to think most 谁帮写篇 最好字数少点

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The person I want to think most 谁帮写篇 最好字数少点

Professor Yuan is widely acknowledged for the discov ery of the genetic basis of heterosis in rice—a pheno menon in which the progeny of two distinctly differen t parents grow faster,yield more,and resist stress bet ter than either parent.In developing his “three-line sy stem” of hybrid rice,Professor Yuan and his team soo n produced a commercial hybrid rice variety called Na n-you No.2,which was released in 1974.With yields 2 0 percent higher than previous varieties,Professor Yu an’s new crop immediately began to improve food av ailability in China.