种间杂交的主要障碍是F1代的不育性.A major barrier to interspecific hybridization is sterility in the F 1 progeny.因此,向日葵细胞质雄性不育性的研究备受关注.That is why cytoplasmic male sterility ( CMS ) in sunflower is the research focus through years....
Each generation surpasses the preceding one.一代更比一代强.Her beauty surpasses all description.她的美丽超出了人力所能描绘的限度.The scenery here surpasses that of the lower reaches of the Changjiang River.此处风光赛过江南....
The crickets chirred plaintively at the foot of the wall.蟋蟀在墙脚下哀鸣.The scent of pine and the sound of crickets floated down from the foothill Appalachians.松树的香味和蟋蟀的鸣叫声从阿巴拉契亚山麓飘送过来.The crickets stridulated their everlastin...