Translate the following passage from Text B into Chinese.What produces and breeds aggression in little boys? It has long been deemed that aggression is induced by male hormones. Scientists today believe that male hormones are only part of the explanation, however. They say aggressiveness in boys is also caused by mothers. From some observations and from conversations with mothers, the scientists have learned something about the treatment of baby boys and baby girls. While the mother keeps her daughter close to her, she trains her son to move away from her, to foster independence.