关于Poisson分布，正确的是（）

A.总体均数与总体标准差相等

B.其概率函数图不可能出现负偏峰的图形

C.假定每10分钟内记录到的放射性脉冲数服从Poisson分布，若在某10分钟内记录值为X，则2X可看成是20分钟内记录到的放射性脉冲数，根据Poisson分布的可加性，它也服从Poisson分布

D.若变量X服从Poisson分布，则它不可能取0值

E.Poisson分布是离散型随机变量的概率分布

Albert Einstein once attributed (把......归因于) the creativity of a famous scientist to the fact that he "never went to school, and therefore kept the rare gift of thinking freely". There is undoubtedly a truth in Einstein’s observation; many artists and geniuses seem to view their schooling as a disadvantage. But such a truth is not a criticism of schools. It is the function of schools to civilize, not to train explorers. The explorer is always a lonely person whether his or her pioneering be in art, music, science, or technology. The creative explorer of unmapped lands shares with tile genius what William James described as the gift for thinking in an unusual way. As schools teach set patterns, they tend to destroy creativity and genius. But if schools could somewhat exist only to cultivate genius, then society would break down. For the social order demands unity and widespread agreement, which r, re destructive to creativity and genius.

Albert Einstein once thought that schools ______.

A．helped develop the creativity of a scientist

B．kept a rare gift for a scientist

C．prevented a scientist from thinking freely

D．contributed a lot to science and technology