Question

阅读下面短文，按照要求完成阅读任务。

Why would human beings waste a third of their lives sleeping when they could be doing more important things like looking after their families or working? Some scientists believe sleeping helps recharge the body, while others think it is important for strengthening newly-formed memories. Now, there is new evidence which suggests that the purpose of sleep may be to forget some of the millions of new things we learn each day.

The neurons in the human brain consist of fibers called dendrites(树突). These grow as we learn new things and connect the brain’s cells to each other at contact points called synapses(突触). The larger the dendrites become and the more cells they connect, the more information we store.

In 2018, Giulio Tononi and Chiara Cirelli, both biologists at the University of Wisconsin-Madison, suggested a new idea: The things our brains learn each day result in so many synapses that things start to get a little messy. Sleeping allows us to sort through(整理) the “noise” and dispense all the unnecessary information, leaving behind only the most important memories.

Recently, the university’s research has provided direct evidence to support the theory. The experiment involved analyzing 6,920 synapses in the brain shavings from two groups of mice over a four-year period; one group had been allowed to sleep, while the other had been kept awake and entertained with toys. The researchers discovered that the brain shavings of the sleeping mice had nearly 20 percent fewer synapses than those that had been kept awake and entertained.

It was also evident during the study that the brain does not shave every synapse. 20% of neurons remained unchanged; these were most likely well-established memories. Therefore, although we may be sleeping to forget some of what we’ve learned, the brain “forgets”in a smart way.

Most researchers believe clearing our brains is not the only purpose of sleep. Resting our minds and bodies has also been found to help with other biological functions like strengthening our immunity. Though scientists may never agree on a single reason, they are all sure of one thing－a good night’s rest is essential for our health. So try and spend at least a third of your day sleeping!

1.What’s the new discovery about the purpose of sleeping according to the text?(no more than 15 words)

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2.What’s the main idea of Paragraph 2?(no more than 10 words)

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3.What does the underlined word “dispense” in Paragraph 3 probably mean?(no more than 5 words)

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4.What agreement do all the scientists probably reach about sleeping according to the text? (no more than 10 words)

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5.What kind of sleeping habit do you have? Please explain.(no more than 25 words)

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Answer

1.To forget some of the millions of new things we learn each day.

2.How the neurons in the human brain help store information.

3.Get rid of. / Do away with. / Take out. / Remove.

4.A good night’s rest is essential for our health.

5.I usually sleep early and get up early, which is a good sleep habit and helps me keep energetic during the daytime.(Open)

【解析】

这是一篇说明文。文章主要讲述了睡眠是为了帮助我们清理大脑里的一些无用信息，同时睡眠也是为了帮助我们恢复身体疲劳，让我们能够更好的学习和生活。

1.细节理解题。根据第一段最后一句Now, there is new evidence which suggests that the purpose of sleep may be to forget some of the millions of new things we learn each day.（现在，有新的证据表明，睡眠的目的可能是忘记我们每天学习的数百万新事物中的一些）可知新的研究发现睡觉的目的是为了忘记我们每天学习的数百万新事物中的一些。故答To forget some of the millions of new things we learn each day.

2.主旨大意题。根据第二段The neurons in the human brain consist of fibers called dendrites.（人类大脑中的神经元由称为树突的纤维组成）以及后文主要说明了人类大脑中的神经元如何帮助储存信息，故第二段主旨大意是人类大脑中的神经元如何帮助储存信息。故答How the neurons in the human brain help store information.

3.词义猜测题。根据第三段Sleeping allows us to sort through the “noise”.leaving behind only the most important memories可知睡眠让我们能够对“噪音”进行分类,能让我们从“噪音”中筛选出所有不必要的信息，只留下最重要的记忆。故可知划线单词意思为“摆脱，删除”，故答Get rid of. / Do away with. / Take out. / Remove.

4.细节理解题。根据最后一段中Though scientists may never agree on a single reason, they are all sure of one thing－a good night’s rest is essential for our health.（尽管科学家们可能永远不会在一个单一的原因上达成一致，但他们都确信一件事——一夜好眠对我们的健康至关重要）可知所有的科学家一致同意晚上好好休息对我们的健康很重要。故答A good night’s rest is essential for our health.

5.本题为开放性题目，言之有理即可。如可答“我通常早睡早起，这是一个良好的睡眠习惯，帮助我在白天保持精力充沛。”。故答I usually sleep early and get up early, which is a good sleep habit and helps me keep energetic during the daytime.