A、Colonial America was a place of different peoples in history. B、Americans are eager to build mutual understanding quickly. C、C

At your next meeting, wait for a pause in conversation and try to measure how long it lasts.
   Chances are—especially among English speakers—it will be a second or two at most.
   Even among sign language speakers, studies show that typically we leave just a fraction of a second between taking turns to talk. But while this pattern may be universal, our perceptions of silence differ dramatically across cultures—a crucial detail if you’re doing business internationally.
   Research conducted at the University of Groningen in the Netherlands in Dutch and also in English found that when a silence in conversation stretched to four seconds, people started to feel unsettled.
   In contrast, a separate study of business meetings found that Japanese people were happy with silences of 8.2 seconds—nearly twice as long as in Americans’ meetings.
   These cultural differences are reflected in the saying in the US that "the squeaky wheel gets the grease" while in Japan it’s reckoned that " a silent man is the best one to listen to. "
   So why do mother-tongue English speakers find long pauses hard to handle?
   In the US, it may stem from the history of colonial America as a crossroads of many different peoples, says Carbaugh. " When you have a heterogeneous complex of difference, it’s hard to establish common understanding unless you talk and there’s understandably a kind of anxiety unless people are verbally engaged to establish a common life," he says. This applies also to some extent to London, he adds.
   In contrast, he says, " When there’s more identity perhaps it’s easier for some kinds of silence to appear. For example, among your closest friends and family it’s easier to sit in silence than with people you’re less well acquainted with. "
Questions 12 to 15 are based on the passage you have just heard.
12. How long can English speakers wait for a pause in conversation at a meeting?
13. What did the research conducted at the University of Groningen find?
14. Why do Americans find long silences hard to handle according to Carbaugh?
15. When will people feel free to sit in silence?