Heart disease is one of the major killers in the world today. Many who suffer from it must have heart transplants (移植). However, it’s difficult to get a suitable heart donation, and even if a patient survives the wait, his or her body often rejects (排斥) the heart.
But there is now new hope for sufferers of heart disease. According to a study published in the journal Advanced Science, researchers from Israel’s Tel Aviv University printed a 3D human heart on April 15.
“This is the first time anyone anywhere has successfully engineered and printed an entire heart,” professor Tal Dvir told CNN.
Unlike the previous 3D-printed heart structure, the new heart is complete with cells, blood vessels (血管), chambers (心室) and other structures a heart needs to function normally. But scientists still have more to figure out before the 3D-printed heart can be fitted into the body. For one thing, the experimental heart is only the size of a thumb (拇指). And, although it can contract (收缩) like a muscle, it cannot pump out blood like a real one. At present, the heart prototype (样品) is like a tiny airplane that has all of the right parts, but can’t fly.
However, the development is still regarded as a major breakthrough in medicine.
In the experiment, the researchers turned human fat tissue (脂肪组织) into human heart tissue with stem cell (干细胞) technology. The tissue was then turned into “bio-ink” for a 3D printer to ensure that tissue in the heart came from the patients themselves. So ideally, if it were to be placed in the body of someone in need of a transplant, there would be less risk of organ rejection.
“Patients will no longer have to wait for transplants or take medications to prevent their rejection,” researchers told USA Today. “Instead, the needed heart will be printed, fully personalized (个性化的) for every patient.”
But the scientists think that 3D printing can be used to create other human organs. They foresee a time when the 3D printing of organs will be an everyday medical practice.
“Maybe, in 10 years, there will be organ printers in the finest hospitals around the world and these procedures will be conducted routinely,” Dvir said.
1.Why is the 3D-printed heart important?
A.It will be used on a patient.
B.It is the first 3D-printed heart.
C.It will replace a heart donation.
D.It has a complete heart structure.
2.What problem do 3D-printed hearts have?
A.They cost too much. B.They are too small.
C.They can’t contract. D.They are hard to produce.
3.Why would there be less risk of organ rejection with the 3D-printed heart?
A.It would be made with stem cell technology.
B.It would be made from human fat tissue.
C.It would come from a patient’s body.
D.It would be printed according to the patient’s condition.
4.What attitude does Tal Dvir hold toward the future of 3D printing of organs?
A.Confident. B.Doubtful.
C.Worried. D.Confused.
Have you ever dreamed of meeting top scientists in person? If so, what would you want to ask them? For Tan Fanglin, a 15-year-old girl from No.2 High School of East China Normal University in Shanghai, her dream of meeting top scientists has already come true.
In October, she attended the World Laureates Forum(论坛)for a second time. Tan was by far the youngest participant among the scientists invited to be at the meeting of the world's sharpest minds. Her discovery about the relationship between the Fibonacci sequence(菲波那契数列)and Bézout numbers has won her many prizes in youth innovation competitions. This finding has been praised by the famous Canadian mathematician, Professor Rankin. According to Guangming Daily, Rankin has been studying the same theme for five years but with no conclusions.
From a very young age, Tan has always been fascinated by mathematics. This is largely because of the influence of her father, who teaches mathematics in University. But she had not participated in any Mathematics Olympiad exams before. According to Xu Jun, Tan's head teacher from her middle and high school, she doesn't take after-school classes or too many extra exercises either. Her mastering of Further Mathematics and her good grades in school are thanks to the right study method.
Attending this forum enabled Tan to get more inspiration from top scientists. She asked Professor Miesenbock, the 2019 Warren Alpert Foundation Prize winner, what he considered were the best personal qualities for conducting scientific research. Miesenbock encouraged her not to lose her passion and love for what she does. He stressed that people all knew that even Thomas Edison went through hundreds of unsuccessful attempts before finally inventing the light bulb. Tan has met many barriers in her research and often feels upset. The words made Tan feel inspired. "I will keep my curiosity and interests in mathematics and overcome any obstacles(障碍)in my research," she told Chinese Business View.
1.What does the underlined word "fascinated" in the third paragraph mean?
A.threatened B.refused
C.discovered D.attracted
2.What do we know about Tan Fanglin?
A.Tan has realized her dream of meeting top scientists.
B.Tan is one of the youngest participants in the World Laureates Forum.
C.When she was young，she took part in many Mathematics Olympiad exams.
D.Tan's discovery has achieved a breakthrough after studying the theme for 5 years.
3.What can be inferred from the last paragraph?
A.Tan has seldom met obstacles in her research.
B.Tan often feels undefeated when meeting barriers.
C.Inspired by Miesenbock, Tan is determined to overcome difficulties in research.
D.Tan has the best personal qualities for conducting scientific research in Miesenbock's eyes.
4.What's the best title for the passage?
A.Top Minds Inspire Student.
B.Failure is the Mother of Success.
C.Loving What You Do, a Way to Success.
D.The Elder One Grows, the More He Gets.
It was an extremely cold December night, and I had just settled into the living room sofa with a book when I heard a sharp knocking on the front door. The sound frightened me, mainly because it was 8:45 PM, quite dark outside, and I was alone. My husband had left two days before for a meeting.
I sat thinking for a moment about who could be at my door at that hour. I live on a really quiet street on the North Shore about a block off the main road. Hours can go by without a car or pedestrian(行人)passing in front of my home, a small house that's more than 100 years old.
Another moment passed. More sharp knocking. And then a face pressed against the square window in my front door, with which I made eye contact(接触). A woman's face. She was saying something, but I couldn't make it out.
I wish I could say that the first thing I wanted to do was to jump off the sofa to help this woman, but I hesitated(犹豫)because of all the bad stories about women who open their doors to strangers. What went through my mind was this: What if I open the door and she isn't alone but has an accomplice(同伙)hiding behind that big plant, and then they both come in and kill me?
Still, I opened the door. If I was killed, I had had a good life. She ran into my living room "Gracias. My phone---is dead." Speaking mostly Spanish, but intermixed with bits of English, the woman indicated(暗示)that she was lost, that her phone was dead and that she needed to call her sister who was supposed to have picked her up at the train station but hadn't. So she had decided to try and walk to her sister's but had gotten completely lost in the dark.
I offered to make her some tea while we waited for her phone to charge enough so that she could show me her sister's address.
1.Why does the author mention her surroundings in Paragraph 2?
A.To show off her wealth and social position.
B.To stress her house can seldom be visited.
C.To express her satisfaction with her life.
D.To explain how to find her house easily.
2.How did the author react to the knocking?
A.She turned a deaf ear to it.
B.She answered it immediately.
C.She asked her husband for advice.
D.She thought twice before opening the door.
3.What can we learn about the stranger?
A.She mistook her sister's address.
B.She was a native English speaker.
C.She meant to turn to the author for help.
D.She got in touch with her sister just recently.
4.Which of the following words can best describe the ending of the story?
A.Unusual. B.Relaxing.
C.Frightening. D.Painful.
Camping with kids
The protected lands of the National Parks are some of the most amazing destinations(目的地)to view nature. Here are some of the best national parks for kids.
Grand Canyon National Park
Grand Canyon National Park is a true must-see destination. During the summer months both the South and North Rim are open. The South Rim is busier, but the lodges(小屋)along this side are worth the time to explore. The North Rim offers some great backcountry(偏远地区)activities.
Mesa Verde National Park
Mesa Verde National Park is a great spot to enjoy some of Colorado's amazing archeological (考古的)sites. This park celebrates the history of the Pueblo people in the southwestern United States. Visitors will find over 4,000 archeological sites at Mesa Verde, including 600 cliff dwellings（悬崖屋）.
Grand Teton National Park
Grand Teton National Park is open all year round and offers a wide variety of activities for the whole family as well as summer classes for children. During the winter visitors can enjoy skiing and snowshoeing. In addition, for the most adventurous visitors, Grand Teton National Park has amazing backcountry camping and rock climbing.
Yosemite National Park
Yosemite National Park is an amazing destination for travel enthusiasts, especially rock climbers, and families alike. If you are looking for a less visited spot, Hetch Hetchy is a perfect destination.
1.What do we know about the South Rim?
A.It is closed in summer.
B.It is worthwhile to visit its lodges.
C.It attracts fewer visitors than the North Rim.
D.It offers more activities than the North rim.
2.Which is the best destination for history-lovers?
A.Grand Canyon National Park. B.Grand Teton National Park.
C.Mesa Verde National Park. D.Yosemite National Park.
3.What do Grand Teton National Park and Yosemite National Park have in common?
A.They have few activities in summer. B.They are both crowded places.
C.They are suitable places for rock climbing. D.They provide kids with summer classes.
假定你是李华，计划十一和同学一起去爬贺兰山。请你给外教Nancy 写一封邮件，邀请她一同前往。Helan Moutain贺兰山
内容包括：
1.集合时间及其地点；
2.活动安排及提醒；
3.午餐及返程时间。
注意：1.词数100左右；
2.可以适当增加细节，以使行文连贯。
Dear Nancy,
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
请改正下面短文中的错误。文中共有10处语言错误，每句中最多有三处。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。
This evening I went to Jim’s house to sing with some of my good friend, and we really had a happily time.
It was because of I got a bad score in the math exam that I had been in a low mood for the whole afternoon. But finally, I accepted Jim’s invitation. It was the first time that I have sung with my friends. All my friends enjoy singing, while I didn’t dare to show my voice. I was afraid I couldn’t sing well. After while, my friends noticed this. With our encouragement, I picked up the microphone and sang an English songs, whose name is “ I believe I can fly”. With the song went on, I cheered up and recovered my confidence gradual.
