3,6,6,9,9,12,12,( )A.14 B.15 C.16 D.17 发布时间:2017-06-24 07:17 │ 来源:www.tikuol.com 题型:单项选择题 问题: 3,6,6,9,9,12,12,( )A.14B.15C.16D.17