Quicker and faster 3-D printers have allowed not just amazing objects to be created, but have started to affect how doctors treat patients.

    We've put together a list of some of the most amazingmedical break throughs made possible with 3-D printing.

Life-Saving Airway

    In 2013, doctors created a new airway for kaiba Gionfriddo, aboy born with an airway that kept collapsing (萎陷). To save his life doctors printed tiny tubes to join together in different shapes and sizes until one finally worked for Kaiba. It was placed in Kaiba's bronchus (支气管) so that it no longer collapsed. Even more remarkably, once the plant was placed it couldstay there. It's designed to eventually be absorbed into the body.

New “Bionic” Hands

    One of the most remarkable ways 3-D printing is now being used is as a way to create prosthetics (假肢). A boy born without an arm named Alex was able to get a new“bionic”hand thanks to it. Last year a college student spent 8 weeks coming up with a special prosthetic design that only cost a few hundred dollars in materials. He said he wanted to create a prosthetic far cheaper than other choices that can run tens of thousands of dollars.

A practice Heart

    In Seattle, doctors have been able to use 3-D printing technology to“practice”risky operations so that they will face fewer surprises in the operating room. Kami Sutton was born with her heart“in the wrong place”. For a recent operation her doctor was able to take many scans of Sutton's heart and print out a model. “Kami's heart is truly one-of-a-kind,”Dr. Stephan Seslar, a heart disease specialist said. “Operating on her without understanding the structure of her heart better could be very dangerous.”

A New Skull

    A U.K. man was able to have part of his skull rebuilt thanks toa 3-D printer. Stephen Power broke his cheek bones in a crash. To help Powerh is doctors instead created 3-D bones all carefully printed in the shape of his face. “This is really the first time we've taken it to this stage, where everything has been planned and modeled in advance — and worked sweetly,”said Adrian Sugar, a doctor.

Nowadays more and more people are talking about geneticallymodified foods ( GM foods). GM foods develop from genetically modifiedorganisms (有机体), which havehad specific changes introduced into their DNA by genetic engineeringtechniques. These techniques are much more precise where an organism is exposedto chemicals to create a non­specific but stable change. For many people, thehigh­tech production raises all kinds of environmental, ethical, health andsafety problems. Particularly in countries with long farming traditions, theidea seems against nature.

In fact, GM foods are already very much a part of our lives.They were first put on the market in 1996. A third of the corn and more thanhalf the cotton grown in the U. S. last year was the product of biotechnology,according to the Department of Agriculture. More than 65 million acres ofgenetically modified crops will be planted in the US this year. The geneticgenie is out of the bottle.

However, like any new product entering the food chain, GM foodsmust be subjected to careful testing. In wealthy countries, the debate aboutbiotech is not so fierce by the fact that they have a large number of foods tochoose from, and a supply that goes beyond the needs. In developing countriesdesperate to feed fast­growing and underfed populations, the matter is simplerand much more urgent: do the benefits of biotech outweigh the risks?

The statistics on population growth and hunger are disturbing.Last year the world's population reached 6 billion. The UN states that nearly800 million people around the world are unhealthy. About 400 million women ofchildbearing age don' t have enough iron, which means their babies are exposedto various birth defeats.As many as 100 million children suffer from vitamin Adeficiency, a leading cause of blindness.

How can biotech help? Genetic engineering is widely used toproduce plants and animals with better nutritional values. Biotechnologistshave developed genetically modified rice and they are working on other kinds ofnutritionally improved crops. Biotech can also improve farming productivity inplaces where food shortages are caused by crop damage attributable to drought,poor soil and crop viruses.

    Andy was still traveling in Spain when he realized he had to confirm (确认) his flight home with the airline company (航空公司). He was visiting Spain in order to improve his Spanish. When he was speaking to people face to face, he had no difficulty understanding what they said. However, when he was speaking on the phone, he still had a problem. Andy called the airline. And the clerk confirmed that his plane was leaving at nine o'clock three days from that day. She also told Andy to be at the airport two hours earlier in order to check in his luggage and get a seat.

    Since he was leaving in three days, Andy didn't lose any time. He visited as many places as he could. He thought that it would probably be a while before he had enough money again. He wished he could come back and spend a year in Spain.

    Too quickly, the final day arrived. Andy left early for the airport to arrive two hours before take-off. He hated to rush. He went to the clerk to show his ticket. The clerk looked at the ticket in surprise. "Why, sir, but your flight was at nine o'clock in the morning, and now it is eight in the evening." "But I confirmed my flight," insisted Andy. "Will I have to pay for another ticket?"

    "No, sir. However, the next flight out will be three days from now."

    Andy's look of shock turned to pleasure as he realized that now he could continue his vacation.

    At least five wolves, including one female, have returned to Denmark for the first time in two centuries, a zoologist who has obtained DNA evidence said on Thursday.

    The wolves came from Germany to settle in western Denmark's agricultural region, the least densely populated in the Scandinavian country. Peter Sunde, a scientist at the University of Aarhus, told AFP the wolves must have walked more than 500km. "We think these are young wolves rejected by their families who are looking for new hunting grounds," the researcher added. Scientists have established a genetic profile from the faeces(f粪便) of five wolves - four males and one female - but there could be more. Sunde said researchers had suspected since 2012 that wolves had entered Denmark. "Now we have evidence [including] that there's one female," signalling the possibility of giving birth this spring, he said.

    Proof was also established through the wolves' fingerprints and video surveillance(监视,监督) showed their location, which scientists refuse to reveal out of fear that it will attract hunters."We're following that. The wolf is an animal we're not allowed to hunt so we must protect it," said Henrik Hagen Olesen, spokesperson at the Danish Environmental Protection Agency.Exterminated by hunters, wolves had been completely extinct in Denmark since the beginning of the nineteenth century.

    In other Nordic countries with a higher wolf population, culling(选择性宰杀) the species, protected by the Bern Convention, is under a fierce debate between inhabitants, farmers, hunters, the government, the European Union and wildlife activists.

    Recently, people in US education have gotten extremely worried because a new report has shown that American students have a math problem.

    The 2015 Program for International Student Assessment(评估)(PISA) shows math scores in the US getting lower and no improvement in science or reading. PISA tests 15-year-olds from different countries and regions in their math, science and reading skills. About 540, 000 students from 72 countries and regions took part in the assessment in 2015.

    US scores in reading and science were about the same as three years ago, leaving Americans near the middle of the bigger group. But the situation in math is much more worrying. The US average score was 470, below the OECD(经合组织)test average of 490, meaning the US was No. 40 among the 72 countries and areas. It was 12 points lower than in 2012 and 18 points lower than in 2009. So, what is going on with American students' math skills?

    One reason may be that the US does not teach math in enough depth. "Students are often good at answering the first part of a problem in the United States, "said Andreas Schleicher, director of education and skills at OECD. "But as soon as students have to go deeper and answer the more complicated part of a problem, they have difficulties. "In comparison, many high-performing countries and regions in math teach a lot less but focus in much greater depth,  especially when you look at East Asia, Japan and Singapore, according to Schleicher.

    Another reason may be the fact that many people in the US are unwilling to travel to foreign countries to learn better teaching practices. "One of our biggest challenges in the US is that the teachers are not going out and seeing what high-performing countries do differently, "said Wendy Kopp, who started Teach for America, in a news program.

    Whenever we turn on the TV or radio, read the newspapers, or surf the Internet, we'll be surrounded by the word “diet” everywhere. We have so easily been attracted by the promise of diet products that we have stopped thinking about what diet products are doing to us. We are paying for products that harm us psychologically and physically.

    It's obvious that diet products weaken us psychologically. They allow us to jump over the thinking stage that our weight problems lie not in actually losing the weight, but in controlling the consumption of fat. All we have to do is to swallow or recognize the word “diet” in food labels.

    What's more, diet products have greater psychological effects. Every time we have a zero-calorie drink, we are telling ourselves that we don't have to work to get results. Diet products make people believe that gain comes without pain, and that life can be without resistance and struggle.

    As a matter of fact, the danger that diet products bring not only lies in the psychological effects they have on us, but also in the physical harm they cause. Diet foods and diet pills contain zero calories only because the diet industry has created chemicals to produce these wonder products. And they can indirectly harm our bodies because taking them instead of healthy foods means we are stopping our bodies having basic nutrients. Diet products may not be nutritional, and the chemicals that go into diet products are potentially dangerous.

    Losing weight lies in the power of minds, not in the power of chemicals. Think twice before buying diet products. Once we realize this, we will be much better able to resist diet products, therefore, prevent the psychological and physical harm that comes from using them.