单选题
As a matter of fact, the true nature of communication process can be concluded in one sentence: Who says ______ through what channel to whom.
【正确答案】
A
【答案解析】[解析] 句意：事实上，交流过程的真正本质可以用一句话概括：谁通过什么渠道对谁说了什么。what：什么；when：什么时候；how：怎样；where：哪里。由句意可知，应选what，且what在句中做宾语。其他选项无此用法。