要密切关注广告刊播后的信息反馈情况,从注目率、有效率、()等指标评定数据中,发现广告媒体定位的问题,以便修正。
A.行动率
B.开机率
C.收视率
D.到达率
参考答案:B
Tom's mother always told him not to smoke again, but ()didn't help.
A.he
B.it
C.which
D.as
A.mgtgθ
B.mgsinθ
C.μmg
D.μmg