Dr. Ben Carson rose from poverty to be the head of pediatric neurosurgery at Johns Hopkins Children's Center in Baltimore. His mother raised him by herself, in Detroit, Michigan. Now, the retired surgeon is the first African-American to enter the 2016 presidential race. He is a social conservative with no previous political experience. In his announcement speech, Dr. Carson said he wants to reduce the power of the central government. ___________________________本?卡森医生摆脱贫困,一跃成为巴尔的摩-约翰?霍普金斯儿童中心的儿科神经外科主任.他出生于密歇根底特律,自小由母亲一人抚养.现在,退休的他是首位参选2016年总统竞选的非裔美国人,他是社会保守人士,此前没有任何从政经历. 他在竞选演讲中称希望削弱中央政府的权力,____________________