Questions 46 to 50 are based on the following passage.
【真题来源：2020年7月大学英语四级真题（组合卷）Part Ⅲ，Section C，第51-55题】
Passage Two
It's late in the evening: time to close the book and turn off the computer. You're done for the day. What you may not realize，however，is that the learning process actually continues —in your dreams.
lt might sound like science fiction，but researchers are increasingly focusing on the relationship between the knowledge and skills our brains absorb during the day and the fragmented，often bizarre imaginings they generate at night. Scientists have found that dreaming about a task we've learned is associated with improved performance in that activity ( suggesting that there's some truth to the popular notion that we're “getting”a foreign language once we begin dreaming in it). What's more，researchers are coming to recognize that dreaming is an essential part of understanding，organizing and retaining what we learn.
While we sleep，research indicates，the brain replays the patterns of activity it experienced during waking hours，allowing us to enter what one psychologist calls a neural(神经的) virtual reality. A vivid example of such replay can be seen in a video researchers made recently about sleep disorders. They taught a series of dance moves to a group of patients with conditions like sleepwalking，in which the sleeper engages in the kind physical movement that does not normally occur during sleep.They then videotaped the subjects as they slept. Lying in bed，eyes closed，one female patient on the tape performs the dance moves she learned earlier.
This shows that while our bodies are at rest，our brains are drawing what's important from the information and events we've recently encountered，then integrating that data into the vast store of what we already know. In a 2010 study，researchers at Harvard Medical School reported that college students who dreamed about a computer maze(迷宫) task they had learned showed a 10-fold improvement in their ability to find their way through the maze compared with participants who did not dream about the task.
Robert Stickgold，one of the Harvard researchers，suggests that studying right before bedtime or taking a nap following a study session in the afternoon might increase the odds of dreaming about the material. Think about that as your head hits the pillow tonight.
What is scientists' finding about dreaming?
由题干中的 scientists' finding about dreaming定位到第二段第二句。
细节辨认题。定位句提到，科学家们发现，梦到我们已经学过的一项任务与在该活动中的表现有所提高有关。由此可知，梦到一项学过的任务会改善它的表现，故答案为C。
What happens when one enters a dream state?
由题干中的a dream state定位到第三段第一句。
细节辨认题。定位句提到，当我们进入睡眠，大脑回放它在我们清醒时所经历的活动的模式，使我们进入一种某位心理学家称为神经虚拟现实的状态。由此可知，当我们睡着时，大脑会再一次体验白天的学习活动，故答案为D。
What does the brain do while we are sleeping?
由题干中的brain和 sleeping以及选项定位到第四段第一句。
推理判断题。定位句提到，当我们的身体处于休息状态时，我们的大脑会从我们最近接触到的信息和事件中提取重要信息，然后将这些信息整合到我们已知的大量信息中。提取、整合信息的过程也就是处理、吸收信息的过程。由此可推断，在睡眠状态下，大脑处理和吸收新获得的信息，故答案为C。
What does Robert Stickgold suggest about enhancing learning?
由题干中的Robert Stickgold和 suggest定位到文章最后一段第一句。
细节辨认题。定位句指出，罗伯特• 斯蒂克戈尔德建议，在睡觉前学习或者在下午学习后小睡一会儿，可能会增加梦到这些材料的可能性。由此可知，白天学习后小睡一会儿可能会增加梦到学习材料的可能性，进而提高学习能力，故 A为答案。
What can be inferred about dreaming from the passage?
本题需要统览整篇文章得出答案。
推理判断题。通读全文可知，作者介绍了几个与做梦相关的实验研究，指出做梦可能使人们提高学习能力，故答案为A。