Face-to-face conversation is a two-way process: You speak to me, I reply to you and so on. Two-way (22)_______ depends on having a coding system that is understood by both sender and (23)_______, and an agreed convention about signaling the beginning and end of the message. In speech, the coding system is the language like English or Spanish; the convention that one person speaks at a time may seem too obvious to mention. In fact, the signals (24)_______ in conversation and meetings are often (25)_______. For example, lowering the pitch of the voice may mean the end of a sentence, a sharp intake of breath may signal the desire to interrupt, catching the chairman’s eye may indicate the desire to speak in a formal setting like a debate, a clenched fist may indicate anger. When (26)_______ visual signals are not possible, more formal signals may be needed. 22: A. Exchange B. Interchange C. Communication D. Correspondence 23: A. Announcer B. Receiver C. Messenger D. Transmitter 24: A. That people use B. Are used C. Using D. Being used 25: A. Informal B. non-verbal C. verbal D. formal 26: A. their B. These C. This D. That