Who owns a smartphone?Percentage of adults by age group:Source: The Pew Research Center's Internet&American Life Project of 2,253 American Internet users
21世纪报社版权所有,未经书面授权,禁止转载或建立镜像。 主办单位:中国日报社 Copyright by 21st Century English Education Media All Rights Reserved 版权所有 复制必究 京ICP备13028878号-12京公网安备 11010502033664号