What is the lecture mainly about ?
A.The difference between cognition and metacognition
B.A study showing that dolphins have less cognitive capacity than monkeys
C.The effectiveness of using food as a reward in experiments with monkeys
D.Research that investigates whether animals are aware of feeling uncertainty
答案：D
解析：教授讲了猴子和海豚也许会有metacognition，也就是 feel uncertainty。通过海豚和猴子的实验证明这个结论，但不是把猴子和海豚拿去对比。
Why does the professor mention the inability of animals to report what they are thinking ?
A.To emphasize that language learning is an ability unique to humans
B.To explain why researchers must be sensitive to nuances in animals' behavior
C.To point out a difficulty in testing for metacognition in animals
D.To show the need for advancements in the study of animal communication
答案：C
解析：Researchers have long been interested in whether possess this capability but they couldn’t test it. Because animals are unable to report their feelings.
In the dolphin study, how did the researcher make the dolphin's task increasingly difficult ?
A.By showing the dolphin two patterns that were similar in density
B.By playing two sounds that became progressively closer in pitch
C.By producing sounds that were just within the dolphins' range of hearing
D.By introducing a third paddle that ended on trial an began a new one
答案：B
解析：The closer we came in pitch to the first one, the harder will be for the dolphin to correctly identify as it lower. 这些比较说明是通过逐渐改变pitch来实现难度增加的。
According to the professor, what objections did some researchers raise with regard to the dolphin study?
A.The study did not distinguish between learned and higher-level responses.
B.The dolphin was not rewarded consistently for pressing the third paddle.
C.Only one dolphin was used in the experiment.
D.The results could not be replicated in a later study.
答案：A
解析：But there was a problem, other researchers protested that the response is simply a learned or conditioned response. 对应A项