For centuries, medical pioneers have refined a variety of methods and medicines to treat sickness, injury, and disability, enabling people to live longer and healthier lives.
“A salamander (a small lizard-like animal) can grow back its leg. Why can't a human do the same?” asked Peruvian-born surgeon Dr. Anthony Atala in a recent interview. The question, a reference to work aiming to grow new limbs for wounded soldiers, captures the inventive spirit of regenerative medicine. This innovative field seeks to provide patients with replacement body parts. These parts are not made of steel; they are the real things --- living cells, tissue, and even organs.
Regenerative medicine is still mostly experimental, with clinical applications limited to procedures such as growing sheets of skin on burns and wounds. One of its most significant advances took place in 1999,when a research group at North Carolina’s Wake Forest Institute for Regenerative Medicine conducted a successful organ replacement with a laboratory-grown bladder. Since then, the team, led by Dr. Atala, has continued to generate a variety of other tissues and organs 一 from kidneys to ears.
The field of regenerative medicine builds on work conducted in the early twentieth century with the first successful transplants of donated human soft tissue and bone. However, donor organs are not always the best option. First of all, they are in short supply, and many people die while waiting for an available organ; in the United States alone, more than 100,000 people are waiting for organ transplants. Secondly, a patient’s body may ultimately reject the transplanted donor organ. An advantage of regenerative medicine is that the tissues are grown from a patient’s own cells and will not be rejected by the body’s immune system.
Today, several labs are working to create bioartificial body parts. Scientists at Columbia and Yale Universities have grown a jawbone and a lung. At the University of Minnesota, Doris Taylor has created a beating bioartificial rat heart. Dr. Atala’s medical team has reported long-term success with bioengineered bladders implanted into young patients with spina bifida (a birth defect that involves the incomplete development of the spinal cord). And at the University of Michigan, H. David Humes has created an artificial kidney.
So far, the kidney procedure has only been used successfully with sheep, but there is hope that one day similar kidney will be implantable in a human patient. The continuing research of scientists such as these may eventually make donor organs unnecessary and, as a result, significantly increase individuals'chances of survival.
1. In the latest field of regenerative medicine, what are replacement parts made of?
A. Cells, tissues and organs of one’s own.
B. Rejected cells, tissues and organs.
C. Donated cells, tissues and organs.
D. Cells, tissues and organs made of steel.
2.What have scientists experimented successfully on for a bioartificial kidney?
A. Patients. B. Rats. C. Soldiers. D. Sheep.
3.Why is generative medicine considered innovative?
A. It will strengthen the human body’s immune system.
B. It will provide patients with replacement soft tissues.
C. It will make patients live longer with bioartificial organs.
D. It will shorten the time patients waiting for a donated organ.
4.What is the writer’s attitude towards regenerative medicine?
A. Doubtful. B. Reserved. C. Positive. D. Negative.
年級(jí) | 高中課程 | 年級(jí) | 初中課程 |
高一 | 高一免費(fèi)課程推薦! | 初一 | 初一免費(fèi)課程推薦! |
高二 | 高二免費(fèi)課程推薦! | 初二 | 初二免費(fèi)課程推薦! |
高三 | 高三免費(fèi)課程推薦! | 初三 | 初三免費(fèi)課程推薦! |
科目:高中英語 來源:2015-2016學(xué)年廣東湛江第一中學(xué)高一上學(xué)期期中英語試卷(解析版) 題型:書面表達(dá)
書面表達(dá)
假定你是李華,從互聯(lián)網(wǎng)(the Internet)上得知一個(gè)國際中學(xué)生組織將在新加坡(Singapore)舉辦夏令營,歡迎各國學(xué)生參加。請(qǐng)寫一封電子郵件申請(qǐng)參加。
內(nèi)容主要包括:
1.自我介紹(包括英語能力);
2.參加意圖(交朋友、介紹中國、了解其他國家);
3.希望獲準(zhǔn)。
注意:1.詞數(shù)100左右;
2.可以適當(dāng)增加細(xì)節(jié),以使行文連貫;
3.郵件開頭和結(jié)尾已為你寫好。
Dear Sir or Madam,
Yours,
Li Hua
查看答案和解析>>
科目:高中英語 來源:2015-2016學(xué)年山東蒙陰一中高二學(xué)優(yōu)班10月模塊測(cè)試英語試卷(解析版) 題型:七選五
This Way to Dreamland Daydreaming means people think about something pleasant, especially when this makes them forget what they should be doing. Daydreamers have a bad reputation for being unaware of what’s happening around them. They can seem forgetful and clumsy._1._They annoy us because they seem to be ignoring us and missing the important things.
But daydreamers are also responsible for some of the greatest ideas and achievements in human history. __2._ Can you imagine what kind of world we would have without such ideas and inventions?
So how can you come up with brilliant daydreams and avoid falling over tree roots or otherwise looking like a fool?
First, understand that some opportunities(機(jī)會(huì)) for daydreaming are better than others. Feeling safe and relaxed will help you to slip into daydreams.__3._ And if you want to improve your chances of having a creative idea while you’re daydreaming, try to do it while you are involved in another task—preferably something simple, like taking a shower or walking, or even making meaningless drawings.
It’s also important to know how to avoid daydreams for those times when you really need to concerntrate. “Mindfulness”, being focused, is a tool that some people use to avoid falling asleep.__4.__
Finally, you never know what wonderful idea might strike while your mind has moved slowly away.___5._
Always remember that your best ideas might come when your head is actually in the clouds.
A. Having interesting things to think about also helps.
B. They stare off into space and wander by themselves.
C. Without wandering minds, we wouldn’t have relatively, Coke or Post-it notes.
D. At one time, daydreaming was thought to be a cause of some mental illnesses.
E. It involves slow, steady breathing for self-control that helps people stay calm and attentive.
F. Daydreams are often very simple and direct, quite unlike sleep dreams, which may be hard to understand.
G. Therefore, it’s a good idea to keep a notebook or voice recorder nearby when you’re in the daydream zone.
查看答案和解析>>
科目:高中英語 來源:2014-2015學(xué)年湖南省懷化市高三一?荚囉⒄Z試卷(解析版) 題型:完形填空
完形填空
Leaving for work one morning, I noticed that my newspaper hadn’t been delivered yet.Since I always took it to work, it me that I would have to stop at the store and pick one up.I was already running late, but figured I could make it if I hurried. It was putting me in a . mood.
As I pulled into the parking lot of the to get a newspaper, I noticed a young man in a wheelchair who seemed to be with his wheelchair.“I’m sure he’s all right”, I thought, “or if he’s not, someone else will help him.”
by the customers and cars that were passing him by, I guessed they were thinking the thing.I got out and walked over to see what the was.
“Is there anything I can do?” I asked. I noticed he wasn’t able to , and was still struggling with the wheelchair.
I at the wheelchair and noticed that the clamp(夾鎖) holding the electronic keyboard and chair controls had loosened, causing the equipment to slip down, out of his reach.
I pulled it back into .His hand pulled over to the keyboard and he hit a single key.An electronic voice said, “Thank you.”
I felt a wave of gratitude come over me. I was truly blessed to have the physical .that allowed me to live a normal life.The young man helped me gain a new way of thinking in life.
1.A. annoyed B. ignored C. permitted D. avoided
2.A. guilty B. curios C. bad D. good
3.A. office B. store C. library D. station
4.A. comparing B. living C. struggling D. playing
5.A. Judging B. Waiting C. Attracted D. Interrupted
6.A. particular B. happy C. same D. strange
7.A. accident B. trouble C. comment D. surprise
8.A. share B. deliver C. move D. speak
9.A. look up B. look down C. come down D. hold up
10.A. gradually B. luckily C. suddenly D. obviously
11.A. space B. form C. place D. shape
12.A. gratitude B. attitude C. manner D. ability
查看答案和解析>>
科目:高中英語 來源:2014-2015學(xué)年河北永年第二中學(xué)高三12月月考英語試卷(解析版) 題型:閱讀理解
Speaking from my past experience, it is very difficult to find good friends that you can trust but once you have found them, they are worth keeping forever! Therefore, I think friendship is the most important relationship that anybody could have.
The qualities I look for in a friend are a good sense of humor but sensitivity when it matters. Also that friend would have to be strong-minded and highly spirited. I think that these qualities are the key qualities to look for in a good friend.
Even the strongest friends can still have arguments, although usually about more serious topics, rather than the usual teenage childish arguments. Some matters can seriously affect a friendship. If one of your friends started experimenting with harmful and dangerous drugs, what would you do ? A good friend would try to help as much as possible, whereas a bad example of a friend would simply shrug(聳肩) and turn a blind eye.
Not only the bad things affect friendship ---- good activities do too. Such as bonding with one another, not just by going out on a night with them but by spending quality time with them and talking to each other, which indicates a good ability to communicate. This is a key aspect of a good friendship.
Good friends do not always have to be in the same age group as you. I have a good friend and she is 47 years old and I am 16.
Unfortunately, some people lose contact with their friends as they grow older, which is a sad way to lose a good friend.
I think friendship is one of the most important things in life because if you have no friends you will have no happiness.
1.According to the author, true friendship _______.
A. is easy to get
B. deepens with time
C. needs management
D. affects one’s happiness
2.Paragraph 3 is mainly about______.
A. why drugs are bad for teenagers
B. problems that will test friendship
C. ways that help avoid arguments
D. whether a friend is trustworthy
3.According to the author, which matters least in friendship?
A. Age. B. Sensitivity.
C. Sense of humor. D. Communication ability.
4.Which of the following saying can match the author’s view on friendship?
A. Old friends and old wines are best.
B. A friend without faults will never be found.
C. A life without a friend is a life without the sun.
D. a friend to everybody is a friend to nobody.
查看答案和解析>>
科目:高中英語 來源:2016屆四川成都市高三10月階段性考試英語試卷(解析版) 題型:語法填空
閱讀下面材料,在空白處填入適當(dāng)?shù)膬?nèi)容(1個(gè)單詞)或括號(hào)內(nèi)單詞的正確形式。
China’s V-Day parade not only makes clear its key role in defeating fascism(法西斯)but also shows that a powerful, modern nation has emerged already. There is 1. African proverb that says, “Until a son is old enough, he will not bother 2. (ask) what killed his father in order to take revenge.” The ceremony demonstrated that China has come of age and can no longer be ignored by the rest of the world.
No 3. (few) than 17 countries sent a total of 1,000 troops to take part in the parade, joining 12,000Chinese troops in Tian’anmen Square. China displayed a series of modern military hardware including tanks, fighter jets and ballistic missiles(彈道導(dǎo)彈).
On the day of the parade, Xi said the day would go down in history in remembrance of the 4. (remark) times in 5. the world stood against Japanese aggression. While thanking the world leaders who stood 6. China, he said that “the war was evil 7. justice won finally”.
Xi said that during the war, great sacrifices were made. Chinese officials say 20 million died and 15million 8. (wound) in China. Xi said China also will always remember the9. (contribute)of other countries in the defeat of Japan during the war.
While 10. (say) that China loves peace, he announced that China would reduce its military forces by 300,000 troops by the end of 2017.
查看答案和解析>>
科目:高中英語 來源:2016屆廣西武鳴縣高級(jí)中學(xué)高三8月月考英語試卷(解析版) 題型:完形填空
完形填空
I was a single parent of four small children, working at a low-paid job. Money was always tight, but we had a ________ over our heads, food on the table, clothes on our backs, and if not a lot, always ________ . Not knowing we were poor, my kids(孩子們) just thought I was ________ . I’ve always been glad about that.
It was Christmas time, and although there wasn’t ________ for a lot of gifts, we planned to celebrate with a family party. But the big ________ for the kids was the fun of Christmas ________ .
They planned weeks ahead of time, asking ________ what they wanted for Christmas. Fortunately, I had saved $120 for ________ to share by all five of us.
The big ________ arrived. I gave each kid a twenty-dollar bill and ________ them to look for gifts of about four dollars each. Then everyone scattered(散開). We had two hours to shop; then we would ________ back at the “Santa’s Workshop”.
Driving home, everyone was in high Christmas spirits, ________ my younger daughter, Ginger, who was unusually ________ . She had only one small, flat bag with a few candies — fifty-cent candies! I was so angry, but I didn’t say anything ________ we got home. I called her into my bedroom and closed the door, ________ to be angry again. This is what she told me.
“I was looking ________ thinking of what to buy, and I ________ to read the little cards on the ‘Giving Trees.’ One was for a little girl, four years old, and all she ________ for Christmas was a doll(玩具娃娃). So I took the card off the tree and ________ the doll for her. We have so much and she doesn’t have anything.”
I never felt so ________ as I did that day.
1.A. roof B. hat C. sky D. star
2.A. little B. less C. enough D. more
3.A. busy B. serious C. strict D. kind
4.A. effort B. room C. time D. money
5.A. improvement B. problem C. surprise D. excitement
6.A. shopping B. travelling C. parties D. greetings
7.A. the other B. each other C. one by one D. every other one
8.A. toys B. clothes C. presents D. bills
9.A. day B. chance C. cheque D. tree
10.A. forced B. reminded C. invited D. begged
11.A. draw B. stay C. move D. meet
12.A. including B. besides C. except D. regarding
13.A. quiet B. excited C. happy D. ashamed
14.A. since B. after C. while D. until
15.A. waiting B. ready C. hoping D. afraid
16.A. out B. over C. forward D. around
17.A. forgot B. stopped C. failed D. hated
18.A. wanted B. did C. got D. played
19.A. made B. searched C. bought D. fetched
20.A. angry B. rich C. patient D. bitter
查看答案和解析>>
科目:高中英語 來源:2016屆廣西武鳴縣高級(jí)中學(xué)高三9月月考英語試卷(解析版) 題型:語法填空
下面材料,在空白處填入適當(dāng)?shù)膬?nèi)容(不多于3個(gè)單詞)或括號(hào)內(nèi)單詞的正確形式。
Red is used in many American expressions. It can be used to show 1. (happy), as in “a red- letter day”. This is a day when something special happens. The expression is probably based 2. church customs. For almost six hundred years, church calendars(日歷) 3. (mark) with red to indicate special holidays. Today’s calendars are still marked that way with the _4. (meaning) of holidays and special days printed in red.
The expression “a red-letter day” is often heard in everyday life. A red-letter day is 5. day when people are feeling quite happy. It may be a day 6. __ you’ve long waited for, a wedding day, for example, or it may be a day with a happy surprise. You might tell your friends that yesterday was a red-letter day, 7. you won sonic money in the state lottery (彩票).
“Rolling out the red carpet" is another 8. (common) heard expression, which 9. (represent) a warm welcome of any kind. A city may “roll out the red carpet” for its baseball team when the team arrives home after winning the championship.
Red is also used in some expressions that are not happy. Red-handed is one. To be caught red handed is to be caught 10. (perform) a wrong act.
查看答案和解析>>
科目:高中英語 來源:2016屆福建省高三上學(xué)期第三次月考英語試卷(解析版) 題型:閱讀理解
China is going green.In order to reduce air pollution and oil-shortages, car makers have announced their plans to develop hybrid(混合燃料)cars for the Chinese market.Toyota’s hybrid car Prius will be ready to drive in China this week.Let’s have a look at the new car.
Any vehicle is a hybrid car when it combines two or more sources of power.Hybrid cars have special engines, which are smaller than traditional gasoline engine.They run at 99 percent of their power when the car is going at a steady speed. A specially designed battery motor provides extra power for running up hills or when extra speed-up is needed.
Step into a Prius, and turn on the engine.The first thing you notice is how much quieter it is than a traditional car.At this point, the car’s gasoline engine is at rest.The electric motor will provide power until the car reaches about 24 kilometers per hour.If you stay at a low speed, you are effectively driving an electric car, with no gasoline being used, and no waste gas gives off.
The computer makes the decision about when to use a gas engine, when to go electric, and when to use a combination of the two.If you go over 24 kilometers per hour, when you step on the gas, you are actually telling the computer how fast you want to go.
The electronic motor recharges automatically using a set of batteries.When driving at a high speed, the gasoline engine not only powers the car, but also charges the batteries.
Any time you use the brake, the electric motor will work like a generator(發(fā)電機(jī))and produce electricity to recharge the batteries.As a result, the car’s batteries will last for around 200,000 miles.
1.Which of the following pictures can show how the power system of Prius works correctly?(W—Wheel of the car, E.M—electric motor, G.E—gasoline engine, C—computer, B—batteries)
A.
B.
C.
D.
2.What is the most important characteristic of hybrid cars?
A. They are powered by both a rechargeable battery and gasoline.
B. They have smaller engines than traditional gasoline ones.
C. They use only 99 percent of their power to run up hills.
D. They are much quieter than traditional cars.
3.We can know from the report that ___________.
A. the batteries can be recharged at any time you want
B. using the brake suggests that the gasoline engine should work
C. the gasoline engine charges the batteries as well as powering the car
D. the car’s batteries will last for around 200,000 miles without being recharged
4.The author writes this passage mainly to ___________.
A. announce plans to develop hybrid cars for the Chinese market
B. let people know how to save their gasoline when driving a car
C. teach people how to drive a hybrid car
D. introduce a new kind of “green” car
查看答案和解析>>
百度致信 - 練習(xí)冊(cè)列表 - 試題列表
湖北省互聯(lián)網(wǎng)違法和不良信息舉報(bào)平臺(tái) | 網(wǎng)上有害信息舉報(bào)專區(qū) | 電信詐騙舉報(bào)專區(qū) | 涉歷史虛無主義有害信息舉報(bào)專區(qū) | 涉企侵權(quán)舉報(bào)專區(qū)
違法和不良信息舉報(bào)電話:027-86699610 舉報(bào)郵箱:58377363@163.com