单项选择题
A.每次点击收费=0.7 B.每次点击收费=0.8 C.每次点击收费<=0.8 D.每次点击收费=0.6
A.15 B.20 C.22 D.23
A.7:2:1 B.5:3:2 C.5:4:1 D.6:3:1