阅读理解 passage two What we know of prenatal development makes all this attemptmade by a mother to mold the character of her unborn child bystudying poetry, art, or mathematics during pregnancy seemutterly impossible. How could such extremely complexinfluences pass from the mother to the child? There is noconnection between their nervous systems. Even the bloodvessels of mother and child do not join directly. An emotionalshock to the mother will affect her child, because it changes theactivity of her glands and so the chemistry her blood. Anychemical change in the mother's blood will affect the child for better or worse. But we can not seehow a looking for mathematics or poetic genius can be dissolved in blood and produce a similarliking or genius in the child. 　　In our discussion of instincts we saw that there was reason to believe that whatever we inheritmust be of some very simple sort rather than any complicated or very definite kind of behavior. Itis certain that no one inherits a knowledge of mathematics. It may be, however, that childreninherit more or less of a rather general ability that we may call intelligence. If very intelligentchildren become deeply interested in mathematics, they will probably make a success of thatstudy. 　　As for musical ability, it may be that what is inherited is an especially sensitive ear, a peculiarstructure of the hands or the vocal organs connections between nerves and muscles that make itcomparatively easy to learn the movements a musician must execute, and particularly vigorousemotions. If these factors are all organized around music, the child may become a musician. Thesame factors, in other circumstance might be organized about some other center of interest. Therich emotional equipment might find expression in poetry. The capable fingers might develop skillin surgery. It is not the knowledge of music that is inherited, then nor even the love of it, but acertain bodily structure that makes it comparatively easy to acquire musical knowledge and skill.Whether that ability shall be directed toward music or some other undertaking may be decidedentirely by forces in the environment in which a child grows up.