Scientists at Israel's Tel Aviv University say—they have created the world’s first 3D-printed heart with human tissue and blood vessels. Although the organ is only as big as a rabbit’s heart, the researchers are hoping the technology could one day be developed enough to help human patients in need of a heart transplant.
Lead researcher Tal Dvir said that while other scientists have managed to 3D—print the structure of a heart in the past, this is the first time anyone has printed an entire heart. “Our results demonstrate the potential of our approach for engineering personalized tissue and organ replacement in the future,”Dvir said in a press statement.
Scientists used fatty tissue taken from human patients to create the heart. Some material in the tissue was reprogrammed to become stem cells. The remaining material was processed into a hydrogel. They used the hydrogel as a printing：“ink”. This method is key to removing the risk that the implant will be rejected by the patient’s body. The team’s next step is to cultivate the organs in a lab and to teach them how to“behave”like hearts. Dvir’s 3D-printed hearts can currently contract, but the cells still need to develop a pumping ability. His team eventually plans to test the hearts in animals.
“Maybe, in ten years, there will be organ printers in the finest hospitals around the world, and these procedures will be conducted routinely, ”Dvir said. Heart disease is the leading cause of death for both men and women, according to the Centers for Disease Control and Prevention. About 610, 000 people die of this disease in America every year—amounting to about 1 in every 4 deaths. There are currently more than 3700 people waiting for a heart transplant in the United States, according to data from the United States Department of Health and Human Services.
1.What is the purpose of creating the 3D-printed heart?
A.To develop 3D-printed technology. B.To study the hearts of rabbits.
C.To connect hospitals with universities. D.To help patients receive a new heart.
2.Why does the author mention the current situation of heart disease patients?
A.To appeal to hospitals to reduce medical fees.
B.To show the need to improve the new technology.
C.To urge researchers to develop effective medical devices.
D.To introduce the main reason for heart disease to the public.
3.What is the third paragraph mainly about?
A.The course of the research. B.The importance of the research.
C.The material of the 3D-printed heart. D.The method of the 3D-printed heart.
4.What’s Dvir’s attitude towards the new technology?
A.Disapproving. B.Doubtful.
C.Positive. D.Indifferent.
It was a Saturday evening in March，just before sundown，when we heard the screaming. I was out walking with my wife，Melissa，and our golden retriever(猎犬)，Kira，beside a lake when the peace was broken by a woman’s voice，calling out two names over and over.
We spotted her，almost immediately，three or four hundred feet away across the lake. Spring had come but there was still snow on the ground，the water covered by a layer of ice that had just started to thaw. Two big dogs were walking across it. They appeared to be quite old and were moving slowly. As we watched，the ice gave way beneath one dog and then the other，plunging them into the water.
We arrived at the scene a few minutes later，but the dogs already seemed to be showing the effects of the cold as they struggled weakly to escape. We realized that calling 911 would be useless—the dog farther out was in water about 20 feet deep and I feared neither of them would stay afloat long enough for the emergency services to arrive. Besides，I was probably qualified to carry out the rescue myself. I was practicing the kind of deep breathing my grandfather had taught me as I walked in. I wasn’t alone—Kira swam alongside me. Having Kira there was a huge support. We were able to go back to shore quickly.
The second dog was further out and I had to pause before I went back in. That’s when another technique I’d learned from my grandfather came into play. He’d taught me about a pressure point on the wrist that when pressed in the right way sends out an electrical signal，like a jolt of energy. That kept me warm as I set out again with，Kira. I maintained eye contact with the dog as we approached. With Kira’s encouragement，it followed us back. The owner was emotional—“I’m the luckiest woman alive!”she said.
1.What does the underlined word“thaw”in Paragraph 2 probably mean?
A.Melt. B.Shake.
C.Flow. D.Appear.
2.Why didn’t the writer call 911?
A.The writer’s dog has been trained to save lives.
B.The dogs could save themselves from the cold water.
C.There wasn’t enough time to wait for the emergency services.
D.The writer’s grandfather had taught him how to save the dogs.
3.What do we know about the second technique the writer learned from his grandfather?
A.It makes him brave. B.It keeps him warm.
C.It allows him stay focused. D.It helps him walk quickly.
4.Who accompanied and helped the writer while saving the dogs in the water?
A.His wife. B.The dogs’owner.
C.His grandfather. D.His dog.
While gardens can be a great place for pets to explore and play, some seemingly harmless plants and gardening products can be poisonous for animals or pets. Here are the garden products to avoid:
Cocoa mulch
Some gardeners like to use cocoa shell mulch in their gardens but, just like chocolate, cocoa shell mulch contains theobromine (可可碱), which is poisonous to dogs. This means that cocoa shell mulch can be potentially deadly if consumed in large quantities. If you own a dog I’d strongly advise that you avoid using Cocoa mulch in your garden.
Compost
Despite being an eco-friendly garden feature, compost can be highly dangerous for animal. As organic matter decomposes, it releases mycotoxins (霉菌素), which are poisonous to wildlife. Consumption of mycotoxins can cause panting, vomiting (呕吐), seizures and even death in dogs. If you do use compost in your garden, make sure it is securely fenced off so that your pet cannot access it.
Weed killer
The chemicals contained in weed killers can be irritants to animals and, in some cases，even poisonous. Some weed killers contain harmful substances, such as borax and arsenic, which can potentially be fatal to pets. If you are unsure whether a weed killer is safe to use in a garden that your pet uses, you should always seek the manufacturer’s advice first, or ask a vet (兽医).
Fertiliser
Different fertilisers can contain a wide range of ingredients, including insecticides, fungicides and bacterial. The caustic nature of some fertilisers also means that, if consumed, they can cause stomach upsets for pets. Some fertilisers can also cause more serious symptoms, such as vomiting, muscle tremors or even death, so keeping your garden fertiliser free is the simplest way to ensure that it is pet friendly.
If you think your pet has eaten something they shouldn’t, or if you have any other concerns about your pet’s health, you can call the video vet service FirstVet at any time of day and speak with a qualified UK vet.
1.Which of the following gardening products could cause your pets vomit?
A.Fertiliser and compost. B.Cocoa mulch and compost.
C.Weed killer and fertilizer. D.Cocoa mulch and weed killer.
2.What do we know from the text?
A.Compost can be used freely in a garden.
B.All weed killers can kill your pets.
C.Too much Cocoa mulch can kill your pets.
D.Fertilisers containing different ingredients are pet friendly.
3.What is the purpose of the text?
A.To introduce some tips to treat your pets.
B.To inform you of how to protect your pets.
C.To warn you of what can harm your pets.
D.To tell you how to make your garden pet friendly.
假定你是李华，你所在的学校要征集一封英文感谢信，以致意奋战在抗击新型冠状病毒肺炎第一线的医护人员，请你根据下列要点写一封信用于投稿。
1. 表达谢意； 2. 个人感受； 3. 表达信心。
注意：1.词数120左右；
2.可以适当增加细节，以使行文连贯；
3.开头语和结束语已为你写好。
参考词汇：流行病epidemic 疫情 epidemic situation 新型冠状病毒 novel corona virus
Dear Medical workers，
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Yours sincerely,
Li Hua
假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。
增加：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。
删除：把多余的词用斜线（＼）划掉。
修改：在错的词下画一横线，并在该词下面写出修改后的词。
注意：
1. 每处错误及其修改均仅限一词；
2. 只允许修改10处，多者（从第11处起）不计分。
It is common that some people can accomplish very tough tasks while other can’t. In reality, no one can always avoid difficulties in life, but the results are quite differently. The difference lay in people’s different attitudes. Some people choose to face hardships bravely. We are determined to reach their destinations how many times they fail. Therefore, it’s just their perseverance which helps them make it in the end. Others may easily give up to whatever obstacle they meet, which can lead to nothing but failure.
In my view, keep on doesn’t necessarily mean success, but giving up absolutely means failures. If we can adopt such positive attitude, we are bound to achieve more than we expect.
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。
Qian Xuesen, a gifted rocket scientist 1. led China's space and rocketry programs, was born in Shanghai in December 1911. He 2. (admit)into Shanghai Jiao Tong University in 1929. In1934, he won 3. scholarship and in 1935 he left China to study at the Massachusetts Institute of Technology. One year later, he 4. (go)to the California Institute of Technology to start graduate studies under Theodore yon Kármán, a world-famous professor of aerodynamics(空气动力学).
From 1938 to 1955, Qian stayed in America, working with Kármán to research aerodynamics, rocketry and missiles. Despite his high salary and comfortable life in the US, Qian remained 5. (concern)about his home country's development. In October 1955, Qian braved all the difficulties and 6. (final)made his way back to China.
Upon his arrival, Qian Xuesen, together 7. dynamics expert Qian Weichang, established the Institute of Mechanics. Then Qian set out 8. (1ead)China's missile and rocketry programs.
Uninterested in fortune and fame, Qian devoted his life to 9. (rebuild)the nation. ''As a Chinese technician, my life's purpose is to serve the people, '' he said. ''If after I die the public feels I have made a contribution during my life, that 10. (approve)will be the highest praise of all. '' Qian died on Oct. 31, 2009. The Chinese people will never forget his contribution.
