We take showers and use the toilet every day to get rid of bodily waste. Our brains also need to take a bath every day. How can they do it?
A 2013 study found the answer. Researchers at the US University of Rochester studied the brains of mice and discovered that they cleaned themselves while the mice slept. A kind of fluid (液体) in the brain, called cerebral spinal fluid (CSF, 脑脊液), was found to increase dramatically (显著地) during sleep, washing away waste proteins that had been building up between brain cells in waking hours.
“This study shows that the brain has different functional states when asleep and when awake,” Maiken Nedergaard, the lead researcher, told NBC News. It also explains why we can’t seem to think clearly after a sleepless night while a good night’s sleep leaves us feeling sharp and refreshed.
Now a new study, published on Oct. 31 in Science, digs a little deeper into our brains’ self-cleaning procedure. Instead of mice, this time humans were the test subjects.
Researchers at Boston University, US, monitored the brainwaves of 13 healthy adults who were sleeping, using accelerated FMRI (核磁共振成像), which is capable of recording faster changes inside the brain than a regular FMRI machine. They found that every 20 seconds, blood flowed out of the brain, making room for a large amount of CSF to come in and “clean”. This cycle coincided with (与....一致) the rhythm of the brain’s slow waves—an electrical activity that happens when we’re in a deep sleep.
It’s still unknown how these brain activities are connected. But the mere fact that they are connected is exciting enough, since it allows researchers to piece together (拼凑出) possible new explanations for misunderstood diseases.
For example, slow-wave sleep has been proven to play a role in strengthening our memories. This may explain why people with Alzheimer (阿尔茨海默病) often have fewer and weaker slow brainwaves. Based on this new study, there could be one more explanation for diseased brains: They are not clean.
Nedergaard, leader of the 2013 study, is also excited about the new findings. “Maybe the most important take-home message is that sleep is a serious thing,” she told Scientific American. “You really need to sleep to keep a healthy brain because it links electrical activities to a practical ‘housekeeping’ function.”
1.What did the researchers find when they studied the brains of mice?
A.CSF in their brains decreased when the mice slept.
B.More waste proteins were produced in their brains during sleep.
C.CSF carried away waste proteins in their brains during sleep.
D.The more CSF was in their brains, the fewer proteins were there.
2.What did the researchers discover when they monitored human brainwaves?
A.It took 20 seconds for CSF to clean brains.
B.Brains were “cleaned” when blood flowed out.
C.The rhythm of the brain was slower than that of CSF.
D.The brains worked more slowly when asleep.
3.What are the last three paragraphs mainly about?
A.The significance of the research.
B.The features of slow-wave sleep.
C.The importance of having a good sleep.
D.The connections between these brain activities.
难度: 困难查看答案及解析
One of the things that I have learned during my time here is that Czech people are really good at celebrating and holding parties. Since I graduated this year, I have a lot of experience of seeing this first-hand. The greatest event for us was definitely the prom (毕业舞会) held for graduating students. Girls started arranging their gowns (礼服) a year beforehand. Graduating students also needed to give their “Midnight Surprise” (a group performance). One interesting thing was that students from every class were holding a huge colorful bag and people had to throw money into it. I didn’t get any sleep that night because we all went to an after-party with our teachers and friends.
At the end of April, we held the traditional activity called “The Last Ringing”, which lasted for two days. Every class had a theme and graduates wore different costumes. We prepared tasty desserts and food to sell. We broke into one classroom after another asking students to give us money, which might seem insane but it is part of the tradition.
By the end of May, we had already finished all of the final exams and we started preparing for the graduation ceremony. It was held in the conference hall (会场) in our school at five o’clock in the afternoon. Parents could come, too. We got our graduation certificate in a gray folder (文件夹) from our class teacher, and we also shook hands with the headmaster. When I received my certificate, I almost teared up-I didn’t want to say goodbye to them or to the school.
That wasn’t the last celebration though. After four days, our class invited all of our teachers to come to a farewell dinner at an Italian restaurant. We used all of the money we collected from the prom and “The Last Ringing” to order pizzas and champagne. We all talked and ate together.
A year ago, we were all complaining and hoping that high school would end. But I felt sad when the time finally came and it was over. We have officially left our school. I keep telling myself that everything has an ending. This journey was amazing. Although it has come to an end, I will always keep the memories I made close to my heart. I won’t ever forget them.
1.What did the author find interesting about the Czech prom?
A.Boys and girls exchanged gifts.
B.Students were required to make gowns by themselves.
C.Students had to bring homemade food.
D.Students used a colorful bag to collect money.
2.What does the underlined word “insane” mean?
A.Reasonable. B.Crazy.
C.Unusual. D.Wonderful.
3.Which would the author probably agree with?
A.She is determined to apply to a Czech university.
B.She should have worked harder at school.
C.She values the wonderful memories from high school.
D.She prefers the farewell party over the “The Last Ringing”.
难度: 中等查看答案及解析
Queen Elizabeth Ⅱ has led Great Britain through many tough times throughout her 68-year sovereignty (在位). But never, during her reign (统治), has an issue disrupted the British public as much as the current pandemic of COVID-19.
By April 6, the UK had had 47,806 confirmed cases. Among them, crucially, is British Prime Minister Boris Johnson, who has recently been hospitalized. With the country entering its peak infection period, the Queen made only her fifth televised address to the nation, aside from her annual Christmas broadcast, on April 5. The four other times she has made such an address have been to mark the Gulf War, the death of Princess Diana of Wales, the death of her mother and her Diamond Jubilee (登基六十周年纪念).
Accord win to Jonny Dymond, the BBC’s royal correspondent, “The Palace could have played it safe, stressed unity and given thanks. But this speech was designed to reassure (使安心) and inspire.”
In her pre-recorded statement, the Queen focused on the commitment of her subjects. “We have seen heart-warming stories of people coming together to help others.”
As well as thanking frontline workers, she pushed a message of comfort and motivation. “Together, we are tackling (处理) this disease, and I want to reassure you that if we remain united and resolute (坚决的), then we will overcome it.”
“We should take comfort that while we may have more still to endure, better days will return; we will be with our friends again; we will be with our families again; we will meet again.”
Following the speech, people throughout the country voiced their admiration for her moving words.
London Mayor Sadiq Khan praised the Queen’s focus on frontline healthcare workers, and councilor (议员) Oliver Cooper wrote, “Nobody could have rallied (振作) the country,, the Commonwealth, and the world the way the Queen did.”
Some Internet users even shared how they cried after the speech, while others wrote the words of the national anthem. God Save the Queen.
Indeed, the wisdom of Britain’s 93-ycar-old monarch (君主) offered hope to the millions of Britons under lockdown.
1.What role does the second paragraph play?
A.To offer the latest information about the pandemic in the UK.
B.To inform the reader of the Queen’s televised address.
C.To explain why the address was delivered via television.
D.To indicate the importance of the Queen’s recent speech.
2.What does the phrase “her subjects” in Paragraph 4 refer to?
A.Her family. B.The stories she told.
C.The topics in her speech. D.The citizens under her rule.
3.What are Paragraphs 7-9 mainly about?
A.The focus of the Queen’s speech.
B.The public’s reaction to the Queen’s speech.
C.How the Queen delivered the speech.
D.To whom the speech was addressed.
4.What can we conclude from the text?
A.The UK has never experienced a tougher time.
B.The palace should have played it safe.
C.The Queen’s speech has served its purpose.
D.The Queen was calling on the whole world to unite against CO VID-19.
难度: 中等查看答案及解析
Investing in yourself
Figuring out how to invest your money can be a difficult task. This is something that you will want to learn how to do.
1.Things that will improve your knowledge, skills or health are all great investments. However, before you start, you need to be clear about what you will gain out of doing all of these things.
You may think investing in yourself means investing in your education.2.. There are some other things you can do as well as buying a gym membership or learning a new skill.
So what are some specific things you can do?3.. Reading books can really expand your mind and allow you to learn different skills and gain knowledge. I’m talking about the books where you will actually learn a new skill, not fiction books.
You can also take courses and attend seminars. These programs are taught by people with a high level of knowledge or skill.4.. Only in this way can you avoid being fooled by some sales presentation.
Moreover, investing in yourself is a safe way to keep your money. Although a savings account is seen as the most secure investment, that isn’t 100% safe. Even if you never experience your bank closing down, the return is little when inflation (通货膨胀) is taken into consideration.5.. But over time, they will show up in terms of your happiness level as well as your level of success.
A.The benefits will stay with you.
B.This is just one way.
C.If you aren’t a reader, you should start with that.
D.The more you do this, the more valuable you will be.
E.The best way to invest your money is to invest it in yourself.
F.Of course, you need to do some research before investing.
G.When you invest in yourself, you may not see gains right away.
难度: 中等查看答案及解析
One day when I was 15 years old, I had some friends over to hang out. While we were making food in the ________, my brother came in. He ________ his beef next to my thick one and said, “Courtney, your beef is bigger than mine. You don’t need to eat; you’re already fat enough.” Then he walked out, laughing.
________ comments on my physical appearance were nothing new. Something inside me ________ to his idea that my legs were unacceptable, and that became the last day that I ever willingly wore ________ until I was 30 years old. For the next 15 years, 1 spent summer after summer roasting in long pants.
But then I ________ Ragen Chastain, and she changed everything. I couldn’t believe that this woman who, like myself, almost ________ 300 pounds was so ________ and happy in her own skin. I listened ________ she shared her own journey to recovery and self-love. She talked about how amazing our bodies are, just by ________ of the things they do every day—like ________, pumping blood to every cell, blinking and walking.
Walking! I was suddenly ________ of how foolish I’d been for so long. There’re people who are born ________ legs, or who lack properly working legs, or who ________ their legs, and I’d been ________ my perfectly strong, healthy, beautiful legs in ________ because I had allowed someone to ________ me that they weren’t good enough. The next day. I bought three pairs of shorts and a sundress and spent the entire summer letting my legs sec the sun and feel the breeze.
The next time anyone comments on your body in a ________ way, look them straight in the eye, smile and say, “If what you see ________ you so much, feel free to practice the ancient art of looking somewhere else.” Thai’s Ragen’s original, but I don’t think she’ll ________ if you use it.
1.A.classroom B.kitchen C.bedroom D.dorm
2.A.offered B.devoted C.placed D.organized
3.A.Unpleasant B.Eventual C.Regretful D.Innocent
4.A.took up B.got down C.gave in D.tried out
5.A.shirts B.shorts C.coats D.socks
6.A.asked B.related C.approved D.met
7.A.possessed B.measured C.owned D.weighed
8.A.typical B.energetic C.passive D.respectable
9.A.as B.because C.unless D.though
10.A.feature B.character C.means D.gender
11.A.shopping B.swimming C.breathing D.applauding
12.A.informed B.afraid C.aware D.concerned
13.A.with B.despite C.without D.beyond
14.A.waste B.lose C.reject D.keep
15.A.hiding B.using C.doubting D.blaming
16.A.surprise B.ruins C.puzzle D.shame
17.A.advise B.convince C.inform D.educate
18.A.positive B.negative C.different D.specific
19.A.escapes B.removes C.bothers D.benefits
20.A.wonder B.wander C.suspect D.mind
难度: 困难查看答案及解析
阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。
We are often told to pay attention to 1. our mothers tell us. Most of us enjoy listening to our mothers speaking. Scientists have found that our brains greatly prefer the voices of our own mothers to 2. of other people.
Scientists at the Stanford University, in the United States, recently looked into this. They scanned (扫描) children’s brains while they 3. (listen) to different sounds, including their mothers’ voices. They found that 97 percent of the time, children could recognize their mothers’ voices at once.
4. (hear) their mothers’ voices makes children’s brains more active. We 5. (usual) just use one part of our brain to deal with sounds when we hear something. But when we hear our mothers’ voices, many parts of the brain, including those in charge of reward and emotion, start to work as well.
Why do we respond so strongly 6. our mothers’ voices? It starts even before we’re born. When children are still in the womb (子宫) or have just been born, they hear their mothers talking. This makes babies feel 7. (comfort) and teaches them language and social skills, even though they are still very young. The babies learn to recognize their mothers’ voices as a rewarding sound. Later, when this sound is heard again, more attention 8. (pay) to it.
Some sounds are necessary for our 9. (survive) while others bring us pleasure. Both types are recognized by our brains as rewarding sounds. Most human voices are not recognized in this way, since we hear them so often. 10., mothers’ voices are different, as they bring us a lot of comfort.
难度: 中等查看答案及解析
假设你是红星中学的李华，你校将在下周五举办“校园文化节（Campus Culture Festival）”系列活动。请给你班留学生Jim写封邮件，邀请他参加其中的一个活动。邮件的内容包括：
1. 介绍你推荐的活动；
2. 说明你推荐的理由；
3. 询问对方的意向。
注意：1. 词数80左右；
2. 可以适当增加细节，以使行文连贯。
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难度: 中等查看答案及解析
阅读下面短文，根据所给情节进行续写，使之构成一个完整的故事。
My husband Andrew, a wise father, teaches our kids how to balance risk with freedom.
We have four chickens: Pecky, Buckbeak, Mayonnaise and Cornflake. My husband made their coop (笼子). It’s beautifully made.
Actually he made it with our sons and daughter. The kids and their father spent several weekends in the garage. He gave them tools because he believed it was important that they could actually make something. He slowly helped them and together, they made the coop. They also made the mistakes of learning-a board cut too short, nails smashed (打碎) by hammers — but in the end, Andrew did some tricks and the coop looked perfect.
The chickens loved their perfectly imperfect home and we also gave them free range in the yard. Andrew encouraged our kids to provide the chickens with quite a big area and explained that to take risks is part of life, and by giving chickens the freedom to wander around and dig for bugs, it is a better experience for them than the confines (限制) of the coop.
Yesterday, they ran around the lawn (草地). We needed to go downtown, knowing that chickens wouldn’t go very far. When we got back, my son, Gordon, ran to check on them. There were Mayonnaise, Cornflake and Buckbeak, looking a mess but still alive. Yet Pecky was nowhere to be seen.
With Andrew, we searched the yard and found some feathers by the trees. Then, we saw more feathers littering the yard. By this time. Gordon started to worry; Pecky was his favorite chicken and his eyes got watery.
Andrew picked Gordon up and held him. As we stood there, beginning to accept that we were now a three-chicken family, we heard it-a soft clucking (咯咯声) sound under a bush.
注意：
1. 所续写短文的词数应该为150左右；
2. 至少使用5个短文中标有下划线的关键词语；
3. 续写部分分为两段，每段的开头语已为你写好；
4. 续写完成后，请用下划线标出你所使用的关键词语。
Paragraph 1:
Andrew put Gordon down and they looked under the bush.
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Paragraph 2:
The next day Andrew had a discussion with the kids about what to do with the chickens.
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难度: 中等查看答案及解析