A
(2020·河北省衡水中学高三下学期第一次模拟考试)
We’ve known that sitting for long periods of time every day has countless health consequences，like a higher risk of heart disease.But now a new study has found that sitting is also bad for your brain.
A study published last week，conducted by Dr.Prabha Siddarth at the University of California，showed that sedentary(久坐的)behavior is associated with reduced thickness of the medial temporal lobe(中颞叶)，a brain area that is critical to learning and memory.
The researchers asked a group of 35 healthy people，ages 45 to 70，about their activity levels and the average number of hours each day spent sitting and then scanned their brains.They found that the subjects who reported sitting for longer periods had the thinnest medial temporal lobes.It means that the more time you spend in a chair the worse it is for your brain health，resulting in possible damage to learning and memory.
What is also interesting is that this study did not find a significant association between the level of physical activity and thickness of this brain area，suggesting that exercise，even severe exercise，may not be enough to protect you from the harmful effects of sitting.
It then surprisingly turned out that you don’t even have to move much to enhance cognition(认知)；just standing will do the trick.For example，two groups of subjects were asked to complete a test while either sitting or standing.Participants are presented with conflicting stimuli(刺激)，like the word “green” in blue ink，and asked to name the color.Subjects thinking on their feet beat those who sat by a 3-milicond margin .
The cognitive effects of severe physical exercise are well known.But the possibility that standing more and sitting less improves brain health could lower the bar for everyone.
I know，this all runs counter to received ideas about deep thought，from our grade school teachers，who told us to sit down and focus，to Rodin’s famous “Thinker，” seated with chin on hand.
They were wrong.You can now all stand up.
1．What can we infer from Paragraphs 3 and 4?
A．Severe exercise can lessen the damage of sitting.
B．Severe exercise can greatly improve our brain health.
C．Sedentary behavior will possibly damage our brain.
D．Brain health has nothing to do with sedentary behavior.
2．What does the underlined word “margin” in Paragraph 5 mean?
A．Blank. B．Edge.
C．Decrease. D．Difference.
3．What is the received idea about deep thought?
A．Sitting more is good for our mental health.
B．Sitting is better when we think.
C．Exercise more can improve our cognition.
D．We should stand while thinking.
4．The passage mainly tells us .
A．people tend to sit while thinking
B．standing more can make our brain healthier
C．physical exercise can improve our brain health
D．sedentary behavior leads to countless health problems
【答案】 1.C 2.D 3.B 4.B
【解析】 这是一篇说明文。文章介绍了站着思考能够使人的大脑更加健康、思维更加敏捷的这一现象。
1．推理判断题。由第三段最后一句中的“...the more time you spend in a chair the worse it is for your brain health，...”和第四段中的“...exercise，even severe exercise，may not be enough to protect you from the harmful effects of sitting.”，可知久坐的行为可能会损害我们的大脑。故选C项。
2．词义猜测题。由第五段最后一句“Subjects thinking on their feet beat those who sat by a 32-millisecond margin .”(站着思考的受试者会以32毫秒的差异击败坐着的受试者。)，可知margin在此处意为“差异”。故选D项。
3．细节理解题。根据倒数第二段，这一切都与我们从小学老师那里得到的关于深思熟虑的想法背道而驰，他们让我们坐下集中注意力，还有罗丹著名的“思想者”，手托下巴坐着。可知我们以前接受的关于深思熟虑的想法是坐着思考更好。故选B项。
4．主旨大意题。文章第一段说现在一项新的研究发现，坐着对大脑也有害，后面文章主要介绍了多站立能够使人的大脑更加健康、思维更加敏捷的现象。故选B项。
