拉斯韦尔的“5W”模型,解释为() A: who,towhom,saywhat,inwhichchannel,withwhateffects B: who,towhom,inwhichchannel,saywhat,withwhateffects C: who,saywhat,inwhichchannel,towhom,withwhateffects D: who,inwhichchannel,saywhat,towhom,withwhateffects