2017年12月英语四级考试真题及答案4（第1套）

Section C

Directions:There are 2 passages in this section.Each passage is followed by some questions or unfinished statements.For each of them there are four choices marked A),B),C)and D).You should decide on the best choice and mark the corresponding letter on Answer Sheet 2 with a single line through the centre.

Passage One

Questions 46 and 50 are based on the following passage.

That people often experience trouble sleeping in a different bed in unfamiliar surroundings is a phenomenon known as the"first-night"effect.If a person stays in the same room the following night they tend to sleep more soundly.Yuka Sasaki and her colleagues at Brown University set out to investigate the origins of this effect.

Dr.Sasaki knew the first-night effect probably has something to do with how humans evolved.The puzzle was what benefit would be gained from it when performance might be affected the following day.She also knew from previous work conducted on birds and dolphins that these animals put half of their brains to sleep at a time so that they can rest while remaining alert enough to avoid predators(捕食者).This led her to wonder if people might be doing the same thing.To take a closer look,her team studied 35 healthy people as they slept in the unfamiliar environment of the university's Department of Psychological Sciences.The participants each slept in the department for two nights and were carefully monitored with techniques that looked at the activity of their brains.Dr.Sasaki found,as expected,the participants slept less well on their first night than they did on their second,taking more than twice as long to fall asleep and sleeping less overall.During deep sleep,the participants'brains behaved in a similar manner seen in birds and dolphins.On the first night only,the left hemispheres(半球)of their brains did not sleep nearly as deeply as their right hemispheres did.

Curious if the left hemispheres were indeed remaining awake to process information detected in the surrounding environment,Dr.Sasaki re-ran the experiment while presenting the sleeping participants with a mix of regularly timed beeps(蜂鸣声)of the same tone and irregular beeps of a different tone during the night.She worked out that,if the left hemisphere was staying alert to keep guard in a strange environment,then it would react to the irregular beeps by stirring people from sleep and would ignore the regularly timed ones.This is precisely what she found.

46．What did researchers find puzzling about the first-night effect?

A．To what extent it can trouble people.

B．What role it has played in evolution.

C．What circumstances may trigger it.

D．In what way it can be beneficial.

47．What do we learn about Dr.Yuka Sasaki doing her research?

A．She found birds and dolphins remain alert while asleep.

B．She found birds and dolphins sleep in much the same way.

C．She got some idea from previous studies on birds and dolphins.

D．She conducted studies on birds'and dolphins'sleeping patterns.

48．What did Dr.Sasaki do when she first did her experiment?

A．She monitored the brain activity of participants sleeping in a new environment.

B．She recruited 35 participants from her Department of Psychological Sciences.

C．She studied the differences between the two sides of participants'brains.

D．She tested her findings about birds and dolphins on human subjects.

49．What did Dr.Sasaki do when re-running her experiment?

A．She analyzed the negative effect of irregular tones on brains.

B．She recorded participants'adaptation to changed environment.

C．She exposed her participants to two different stimuli.

D．She compared the responses of different participants.

50．What did Dr.Sasaki find about the participants in her experiment?

A．They tended to enjoy certain tones more than others.

B．They tended to perceive irregular beeps as a threat.

C．They felt sleepy when exposed to regular beeps.

D．They differed in their tolerance of irregular tones.

【参考答案】

46-50：DCACB

【参考译文】

人们经常在不熟悉的环境下睡在不同的床上，这种现象被称为“第一晚”效应。如果一个人第二天晚上呆在同一个房间里，他们往往睡得更香。布朗大学的佐佐木裕卡（Yuka Sasaki）和她的同事们开始研究这种效应的起源。

佐佐木博士知道首夜效应可能与人类的进化有关。问题是，当第二天的表现可能受到影响时，它能带来什么好处。她也知道从以前的工作进行鸟类和海豚这些动物把一半的大脑一次睡觉，这样他们就可以休息，同时保持清醒足以避免捕食者（捕食者）。这让她怀疑人们是否也在做同样的事情。为了更仔细地观察，她的团队研究了35名在大学心理科学系不熟悉的环境中睡觉的健康人。研究人员对这些参与者进行了两晚的睡眠，并对他们的大脑活动进行了仔细的监测。佐佐木不出所料地发现，第一晚的睡眠质量不如第二晚，睡眠时间是第二晚的两倍多，整体睡眠时间也更少。在深度睡眠期间，参与者的大脑表现与鸟类和海豚类似。在第一个晚上，左半球（半球）他们的大脑不睡眠几乎和他们的右脑一样深。

奇怪的是左脑半球是否真的保持清醒来处理在周围环境中探测到的信息。佐佐木重复实验而提出睡觉试与定期定时的哔哔声（蜂鸣声）相同的语气和不规则的哔哔声，夜间不同的基调。她发现，如果左脑半球在一个陌生的环境中保持警觉以保持警惕，那么它就会对不规则的哔哔声做出反应，使人们从睡眠中惊醒，而忽略定时的哔哔声。这正是她的发现。

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2017年12月英语四级考试真题及答案汇总（第1套）