AIDS may be one of the most undesirable diseases in the world. Luckily, there is now hope for AIDS patients.
According to a recent paper published in the New England Journal of Medicine，Chinese scientists have successfully used CRISPR technology -a method of gene editing-to treat a patient with HIV. While it may not have cured the patient fully, it still represents a huge step forward in fighting the disease.
The patient was a 27-year-old Chinese man who was diagnosed with both AIDS and acute lymphoblastic leukemia (淋巴母细胞白血病), a type of blood cancer. Despite his bleak situation, doctors offered him a little hope: a bone marrow (骨髓) transplant to treat his cancer and an experimental treatment for his HIV. They used this chance to edit the DNA in bone marrow stem cells (干细胞) from a donor before transplanting the cells into the patient.
Specifically, the treatment involved using the gene-editing tool CRISPR-Cas9 to delete a gene known as CCR5, which encodes (给…编码) a protein that HIV uses to get inside human cells. Without the gene, HIV is unable to enter cells. Talking about the gene, lead scientist Deng Hongkui told CNN, “After being edited, the cells and the blood cells they produce have the ability to resist HIV infection.” Nineteen months after the treatment, the patients leukemia was in complete remission( 缓 解 ) and donor cells without CCR5 remained, according to the research paper.
Though the transplant didn't cure the man’s HIV, it still showed the effectiveness of gene-editing technology, as there was no indication of any unintended genetic changes-a major concern with past gene-editing treatment experiments. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security in the United States, who was not involved in the study, praised the treatment. “They did a very creative experiment, and it was safe,” he told Live Science. “It should be viewed as a success.”
Deng believes gene-editing technology could “bring a new dawn” to blood related diseases such as AIDS and sickle-cell anaemia ( 镰 状 细 胞 贫 血 ). “Thanks to this new technology, the goal of a functional cure for AIDS is getting closer and closer,” he said.
1.The underlined word “bleak” in Paragraph3 probably means “______”.
A.hopeless
B.unstable
C.embarrassing
D.unique
2.How did the treatment fight against HIV?
A.By identifying and killing HIV.
B.By changing the structure of HIV.
C.By preventing HIV entering cells.
D.By removing a protein HIV feeds on.
3.What is the result of the treatment?
A.Gene-edited cells are able to resist HIV infection.
B.The number of cells infected by HIV has decreased.
C.CCR5 and other genes in the patient's cells are changed.
D.Unintended genetic changes have taken place in the patient's cells.
4.What can we know about the experiment?
A.It pointed out the problems of gene treatment.
B.It provided a new way to cure AIDS patients fully.
C.It could offer a safe treatment for blood-related diseases.
D.It was the first example to use gene-editing tool to treat AIDS.
Something strange has been happening to me lately: Women in the street have been telling me I'm brave.
My act of courage isn't much-I just stopped coloring my hair. I had brown hair that started going gray when I was 30. So, like a lot of women, I started dyeing (染)it. It was expensive and time-consuming. And my hair grows fast, so I needed to go back to the hair salon(美发厅) every 5 weeks.
Many people seem to enjoy holding onto their youth for as long as possible, giving off the impression that they don' t have much wisdom or many accomplishments. But our hair starts to turn gray and suddenly we start spending $500 or more a year to cover something our male colleagues don’t need to cover.
Of course, People should do what they want with their own body -my mother is 91 and still has "blond" hair, and why not? I just wish more of us would feel that it was OK to be ourselves, because going gray has done more for me than saving me time and money.
I like my natural hair, just as it is. I like how it has got curly and full again. It is recovering after years of being damaged by chemicals. I also like that it has given me some needed attitude in a society that makes youth seem so important, while being against maturity. It reminds me that I'm not a kid anymore - and this isn't a bad thing. Not being a kid anymore means I read the books I want, and not the books i feel I should read. It means not wasting my time at events I don' t need to attend when I’d rather be with my family and friends.
When I see my hair in the mirror, it's a reminder that my time is limited, and I should spend it doing what matters. There's nothing shameful about growing older And pretending it's not happening is a way of giving up our power.
I see my gray hair as a little act of rebellion(反叛)against the idea that people lose value as they age, instead of gaining it. I see gray hair as my "flag" and I'm letting it fly proudly.
1.How does the author feel about coloring hair?
A.It shows people’s great courage.
B.It is a good way to hold onto youth.
C.It shows wisdom and accomplishments.
D.It is not worth the time and money spent on it.
2.What should we do when we grow old according to the author?
A.Give up our power.
B.Pretend to be still young.
C.Accept it and act positively.
D.Read as many books as possible.
3.What is the authors main purpose in writing this passage?
A.To explain why youth is valued.
B.To share her opinion on growing older.
C.To stress the importance of different attitudes.
D.To analyze the advantages and disadvantages of aging.
4.Which can be the best title for the passage?
A.Holding Onto Youth
B.Dyeing Your Hair
C.Gaining Value With Age
D.Valuing Wisdom Of Age
If there was a subject at school that made me anxious, it was science. Maybe that’s because in my tenth grade, I couldn't understand my physics teacher's instructions, causing me to accidentally set fire to the classroom. So, when my husband and I decided to home-school our daughters, we made a deal: he would teach science, while I would handle everything else. But that’s not how things have been going these past few weeks, since my husband has been too busy to teach the girls.
Recently, while out on my morning hike before starting lessons, I noticed that the sky was a beautiful blue, and the air was filled with the sweet smell of flowers. That s why I decided that the day’s lessons would be taught outside, although I remembered that my daughters hadn't had any science classes from my husband for a while.
I returned to the house to get the girls ready. We headed up into the forest, settling ourselves by a pond that rarely has any visitors. My daughter Saoirse started to pick up pond weeds and catch frogs, while my other daughter Ula looked at me, waiting to be instructed. I handed her a drawing board and colored pencils. "We wait, "I told her, " and see if something comes along. In the meantime, just draw what's around you.”
We worked for more than an hour, hardly speaking. A bird flew across the water, and then settled in a front of a fallen tree. I quickly told Ula, worried that she’d not seen the creature. But she had, and she started drawing it. An hour later, she’d not finished her picture and I stared down at it. She drew the bird on her paper with amazing accuracy. But there was one other interesting fact about this drawing: she also drew me, sitting beside her.
I realized, as I stared at this child's drawing of us watching a bird, how I'd lived for 40 years, gathered 10 years of higher education, and never understood the foundation of science before this moment. The foundation of science is a sense of wonder; it isn't about accurately reciting words from a textbook. It is first and foremost about stepping outside our busy lives and amazing at the world around us.
1.How did the author feel about science when in school?
A.She was nervous about it. B.She was fond of it.
C.She was confused about it. D.She was eager for it.
2.The underlined word“it” in Paragraph4 refers to“ ”
A.the fallen tree B.the forest
C.the bird D.the picture
3.Which of the following best describes Ula?
A.She's very outgoing. B.She's good at observing.
C.She's very hard-working. D.She shares interests with her sister.
4.What is the foundation of science in the author's opinion?
A.Attention to accuracy.
B.Curiosity about the outside world.
C.Determination to find out the truth.
D.Ability to understand teachers' instructions.
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Tutors Wanted: Math / Science / Humanities + Test Preparation
Job Posted: 2 days ago
Wage: $27 – 30 per hour
Job Type: Part-time
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Job description:
We're looking for tutors to join us before the next school year starts.
Our suitable candidate will be able to assist middle and high school students with test preparation and academic work in Math, Science and / or Humanities.
We'll pay for your training before this fall and can also offer flexible summer tutoring chances, including teaching group classes.
Once our fall semester starts on August 21, we’ll have even higher demand for tutoring sessions on Sundays from 1 p. m. to 8 p.m. as well as from3 p. m. to 9 p. m. Monday-Thursday.
What we offer:
※ Flexible scheduling. Tutors work from 15 to 30 hours per week depending on availability and student demand.
※ Free Sunday dinners during the academic year.
※ Fun staff gatherings
※ Health insurance reimbursement (补偿) for staff working over 30 hours per week.
※ We are 5 minutes’ walking distance from the Menlo Park Caltrain Station.
Applicants must：
※ Have a good command of the subjects they tutor.
※ Be willing to tutor students through the full academic year.
Application instructions:
※ Email us your resume (简历)
※ Tell us why you want to join Academic Trainers and describe your experience of tutoring students if you have any.
※ Let us know your scheduling preferences and potential start date.
※ Tell us which of the subjects you are able to tutor-Math, Science and / or Humanities.
1.Which period of time needs the most tutors during the academic year?
A.Saturday and Sunday mornings.
B.Friday afternoons and evenings.
C.Monday and Thursday mornings.
D.Sunday afternoons and evenings.
2.What can a tutor enjoy who works more than 30 hours per week?
A.Comfortable accommodation.
B.Free job training every month.
C.Health insurance reimbursement.
D.Free meals during the academic year.
3.What qualification should a suitable candidate have?
A.He / She must tutor all the subjects part-time.
B.He / She must be good at the subjects they tutor.
C.He / She must have a previous tutoring experience.
D.He / She must work every evening through the academic year.
It has been discovered that after the age of sixteen, the number of our brain cells begins to decrease at a speed of several million a year. They simply die off. In certain types of activity, the human brain is at its highest point in the early twenties, when it has collected enough information to be able to use the vast number of cells freely in the most effective way. Pure mathematics is one of the fields in which this happens, and we know that Albert Einstein made all his world-shaking discoveries between the age of about 20 and 25, and spent the rest of his life tidying them up and arranging them.
But in certain other types of activity (of which being an author is perhaps one), experience is more important than sharpness of brain, and there one usually finds that a person reaches his or her peak much later in life.
Besides sharpness of brain and experience, here is another thing that is very important, and that is wisdom. One can have a very quick, inventive brain and plenty of experience, but if one uses these foolishly, one harms both oneself and others. Wisdom does not always come with age ——there are plenty of foolish middle-aged people about ——but the average person tends to learn wisdom as he gets older, usually by making painful of embarrassing mistakes. Leaning to be wise is basically learning what is not possible ； and what is possible but so difficult that it is not worth all the trouble one has to go through to get there. Mostly, it is learning about human nature ； how real people behave and react, as against how one would like them to behave and react. One can read and hear lot of idealistic stuff about how to make the world a better place, which would be found if it was based on an accurate observation of human nature, but which is basically a waste of time because it is not.
1.According to the writer, the great discoveries made by Albert Einstein were mainly a result in .
A.years of hard work B.sharpness of the brain
C.rich experience D.his deep understanding of the nature
2.Some people achieve success much later in life because .
A.their work often requires much experience
B.they do not have a chance to show their talents
C.they have to learn lessons from failures
D.they fail to realize earlier the importance of hard work
3.The importance of wisdom lies in the fact that .
A.it helps to avoid various mistakes
B.it contributes to one's creativity
C.it encourages one to go forward in face of difficulty
D.it provides the right direction of efforts
4.The writer came to believe that .
A.it is always a waste of time to make plans about the future
B.it is human nature to make attempts on what looks impossible
C.one should always challenge the impossible to push the society forward
D.one has to use wisdom in deciding what is the best thing to do
Delhi has been the centre of a succession of mighty empires and powerful kingdoms in India. Numerous ruins scattered throughout the territory offer a constant reminder of the area's history, which makes the city always be a fascinating place for tourists.
With the development of the city and more and more people moving, the city has expanded several times in size. That is why it is called New Delhi. New Delhi, a city with a population of over 20 million people, has its newest problem: never before has this city met with the worst air problem.
Air pollution in Indians capital surged to its worst levels in years, covering the city in a thick smog that has become an annual public-health emergency despite government vows to solve the problem.
Hundreds of flights were diverted, delayed and canceled over the weekend due to poor visibility, schools and offices were closed Monday and officials rushed to take emergency measures to try to reverse the eroding air quality. Millions of antipollution masks were distributed at schools, colleges, hospitals and markets.
New Delhi, is engulfed each year as the weather cools and a thick haze builds up from the pollutants emitted from cars and coal-based power plants, swirling dust from construction sites and roads and smoke from crop stubble burning in neighboring states. Fireworks and firecrackers to celebrate the Hindu festival of Diwali then arrives, leaving Delhi the world's most polluted city.
The city's air quality index, which measures a mix of dangerous pollutants, registered an average score of 494 Sunday. That is the highest 24-hour average since Nov. 6 , 2016 , when it hit 497, according to data measured by the Central Pollution Control Board.
1.Which of the following is NOT true?
A.Diwali is one of the most important festivals in India.
B.The government did little to protect its citizens against the serious pollution.
C.Such a serious air pollution in New Delhi appears on a regular basis.
D.The index of the recent air pollution is not the worst in the history.
2.Who may not complain about the serious air pollution?
A.The parents whose children have to stay at home.
B.The pilots whose planes have been diverted or delayed.
C.The manufacturers who produce antipollution masks.
D.The officials who have to work out of their offices.
3.Which of the following phrases can replace the underlined word in paragraph 5?
A.Sent out. B.Sent up.
C.Sent in. D.Sent on.
4.The title of the passage should be .
A.Problems Caused by the Development of New Delhi
B.Dangerous Pollution Envelops New Delhi
C.Antipollution Masks Are in Great Need in New Delhi
D.Farmers in the Neighboring States are to Blame for Burning Crop Stubble
