Moreover,27.6 percent of  those ____preferred reading on their mobile phones, which was 4.6 percent higher than last year.

A． surveying

B．to survey

C． surveyed

D． having surveyed

按《广东电网公司设备缺陷管理规定》，配电运行人员在发现重大缺陷后应立即电话向（）、（）专业专责报告设备缺陷的现场表现情况。