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 (急性淋巴细胞白血病), a type of blood cancer. Despite his hopeless situation, doctors offered him a glimmer of hope: a bone marrow (骨髓) transplant to treat his cancer and an experimental treatment for his HIV.
They used this opportunity to edit the DNA in bone marrow stem cells 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 a protein that HIV uses to get inside human cells. Without the gene, HIV is unable to infiltrate 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 patient’s leukemia was in complete remission (缓解) and donor cells without CCR5 remained, according to the research paper.
Though the transplant did not cure the man’s HIV, it still showed the effectiveness of gene-editing technology, as there was no indication of any unintended genetic alterations - a major concern with past gene therapy experiments.
Amesh Adalja, a senior scholar at the Johns Hopkins Centre for Health Security in the United States, who was not involved in the study, praised the treatment.
“They did a very innovative experiment. 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 anemia (镰刀形细胞性贫血).
“Thanks to this new technology, the goal of a functional cure for AIDS is getting closer and closer,” he said.
1.The technology of CRISPR is to ___________.
A.transplant cells B.encode genes
C.remove proteins D.produce cells
2.What was the result of the treatment?
A.CCR5 and other genes in the patient’s cells were changed.
B.The number of cells infected by HIV decreased.
C.Some of the patient’s blood cells could resist HIV infection.
D.HIV no longer existed in the patient’s cells.
3.What do we know about the experiment?
A.It provided an innovative way to cure AIDS patients.
B.It pointed out the problems of gene therapy.
C.It could offer a safe treatment for blood-related diseases.
D.It’s the first experiment to use gene-editing technology to treat AIDS.
The annual marathon in my town occurred as scheduled. My job was to follow behind the runners in an ambulance in case any of them needed medical attention. As the athletes began to pace themselves, the front runners started to disappear. It was then that my eyes were drawn to the woman in blue running shorts and a baggy white T-shirt.
I knew we were already watching our “last runner”. Her feet were turned in, yet her left knee was turned out. Her legs were so crippled ( 跛足的 ) and bent that it seemed impossible for her to walk, let alone run a marathon.
The driver and I watched in silence as she slowly moved forward. We would move forward a little bit, then stop and wait for her to gain some distance. Then we’d slowly move forward a little bit more. As I watched her struggle to put one foot in front of the other, I found myself breathing for her and urging her forward. I wanted her to stop, and at the same time, I prayed that she wouldn’t.
Finally, she was the only runner left in sight. I sat on the edge of my seat and watched with respect and amazement as she pushed forward with sheer determination through the last miles. When the finish line came into sight, the cheering crowds had long gone home. Yet, standing straight and proud waited a man. He was holding one end of a ribbon tied to a post. She slowly crossed through, leaving both ends of the ribbon fluttering (飘动) behind her.
I don’t know this woman’s name, but that day she became a part of my life — a part I often depend on.
For her, it wasn’t about beating the other runners or winning a prize. It was about finishing what she had set out to do. When I think things are too difficult or I get those “I-just-can’t-do-it,” I think of the last runner. Then I realize how easy the task before me really is.
1.What words can best describe the woman?
A.Proud and determined. B.Strong-willed and honorable.
C.Modest and courageous. D.Diligent and considerate.
2.What has the author learnt from the woman?
A.Don’t depend on others when facing hardships.
B.Nothing is too tough to accomplish if one is brave enough.
C.The disabled can also run a marathon despite their walking difficulty.
D.It’s not winning but holding on straight to the end that really matters.
3.What could be the best title for the text?
A.A Crippled Woman. B.An Unforgettable Job.
C.The Last Runner. D.The Annual Marathon.
听下面一段独白，回答以下小题。
1.Who started talking about running away?
A.The oldest son. B.The middle son. C.The youngest daughter.
2.How did the children react to their mother at first?
A.They were silent. B.They were amused. C.They were upset.
3.What did the daughter say she would turn into?
A.An airplane. B.A boat. C.A car.
4.What happened at the end of the story?
A.The children all went to bed.
B.Everyone had a meal together.
C.The children finally tricked their mother.
听下面一段较长对话，回答以下小题。
1.Where did the woman lose her phone?
A.At her office. B.In a café. C.In a movie theater.
2.What did the guy do when he found the phone?
A.He called the police.
B.He called the last number on it.
C.He called one of the woman’s friends.
3.What does the man suggest the woman do?
A.Give the guy some money.
B.Buy the guy some food.
C.Invite the guy to see a movie.
4.When does the conversation probably take place?
A.At night. B.Around midday. C.In the early morning.
听下面一段较长对话，回答以下小题。
1.Why did the woman get a ticket this morning?
A.She didn”t wear her seat belt.
B.Her kids jumped out of the car.
C.Her kids behaved badly in the car.
2.Who left Jason on the side of the road?
A.His uncle. B.His mother. C.His father.
3.How does the woman feel about what the man said?
A.Interesting. B.Meaningful. C.Hard to believe.
听下面一段较长对话，回答以下小题。
1.Why was the boy late for class?
A.His alarm didn”t go off.
B.He didn”t catch the bus.
C.He was too tired to get up.
2.What will happen to the boy?
A.He”ll fail the class.
B.He”ll take the test later.
C.He”ll get the scholarship.
