47. Usually a conversation happens when twospeakers are in the same setting and notice________
48. When people communicate with each other, theynot only use words but also turn to________
49. To those who overhear a conversation, theyusually cannot well understand the conversation due to the lack of________
50. Conversations, unlike lectures or interviews,allow frequent________
51. In an informal conversation, the lack ofspecific topics can partly result in a sudden change of________
