填空题.A normal conversation between strangers involves more than talk. It also involves the dynamics of space interaction. If one person gets too close, the other person will back up. If the first person invades the other's space again, the other will back up again. The person who finds himself or herself backing up is trying to 11 the distance of the comfort zone. The person closing in is trying to decrease the distance. Most likely neither person is fully 12 of what is going on. In the 1960s American anthropologist (人类学家) Edward T. Hall was a pioneer in study of human behavioral use of space. His field of study became known as proxemics (空间关系学). Hall said that personal space for Americans can be defined as having four 13 zones: the intimate zone within 18 inches of your body for 14 and embracing; personal zone of 18 inches to four feet, for talking with close friends; social zone of four to 10 feet, for talking with 15 ; and the social zone of 10 to 25 feet, for talking to strangers or to a group. Historians say that our 16 of personal space began with the Industrial Revolution in the 18th century. In cities such as London and New York, people of different social and economic classes were 17 crammed together, so they unconsciously developed a commonly understood rule of polite behavior and space to 18 the area around them. People exhibit nonverbal 19 of discomfort when their zones are violated. Invaded people might pull at their hair, become rigid, or even become 20 . As Hall noted in his work, a comfortable conversation needs to include the range of human's personal space. A. similar B. whispering C. restrict D. increase E. insert F. distinct G. standards H. messages I. decrease J. suddenly K. specially L. aware M. angry N. acquaintances O. thinking