单项选择题
A.60M; B.100M; C.500M; D.1G;
A.立即计费; B.24小时内退订免费; C.72小时内退订免费; D.不计取包月费用;
A.立即计费; B.24小时内退订免费; C.72小时内退订免费; D.当月免费;