【正确答案】 B

【答案解析】[听力原文] Well, to continue, as I mentioned earlier, there is also research that demonstrates that individuals perform worse, not better on tasks when other people are there. R.W. Harburt did an interesting experiment. He had his subjects learn a finger maze. This is a game in which you indicate with your finger the way through a complex system of passages or paths. The subjects who had an audience did worse than the subjects who did alone. Now how can we explain these very different results? It seemed very confusing for a long time. Social psychologist, John Roberts, finally cleared up the confusion about why people sometimes perform better and sometimes worse in front of an audience. Roberts found that the presence of an audience facilitates what you already know how to do. That is, if you know what you are doing, having an audience helps you do it better. But if you don't already know how to do something, you will probably make some mistakes and you will make mistakes for a longer time if you have an audience. That's exactly what happened to the subjects who were learning the finger maze. So, if you were doing well, having an audience increases the chances that you will continue to do well. If you were doing badly, having an audience increases the chances that you will continue to do badly. Roberts cleverly pointed out that when you are first learning something, you are better off working alone than practicing with other people. What did the speaker probably discuss before coming to this part of the talk? [解析] 由短文可知，讲话者以前说过，有时有在场的观众对人们的表现起的并非是正面作用，反而是负面作用。短文还有提到说“两种不同的表现”。所以推断，讲话者在这段话之前谈论的是有观众在场时对人们起到的正面影响，故答案为B。

【正确答案】 C

【答案解析】[听力原文] When does the presence of an audience facilitate your performance according to Roberts? [解析] 文中提到罗伯茨的发现，他发现有观众在场会对已经知道该怎么做事的那些人的表现起到促进作用。由此可知，在场观众在当人们非常了解自己所要做的事情时起到好的作用，故答案为C。

【正确答案】 B

【答案解析】[听力原文] What does Roberts think is a better way to learn new things? [解析] 由短文可知，在罗伯茨看来，在一个人学习一样从未接触过的东西时，找个没人的地方去进行练习是最好的，这样做的效果要比与其他人共同练习的效果好。由此可知，学习新东西的更好方法是自己独自努力，故答案为B。