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.

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Plastic-Eating Worms

    Humans produce more than 300 million tons of plastic every year. Almost half of that winds up in landfills(垃圾填埋场), and up to 12 million tons pollute the oceans. So far there is no effective way to get rid of it, but a new study suggests an answer may lie in the stomachs of some hungry worms.

    Researchers in Spain and England recently found that the worms of the greater wax moth can break down polyethylene, which accounts for 40% of plastics. The team left 100 wax worms on a commercial polyethylene shopping bag for 12 hours, and the worms consumed and broke down about 92 milligrams, or almost 3% of it. To confirm that the worms' chewing alone was not responsible for the polyethylene breakdown, the researchers made some worms into paste(糊状物) and applied it to plastic films. 14 hours later the films had lost 13% of their mass — apparently broken down by enzymes (酶) from the worms' stomachs. Their findings were published in Current Biology in 2017.

    Federica Bertocchini, co-author of the study, says the worms' ability to break down their everyday food — beeswax — also allows them to break down plastic. ＂Wax is a complex mixture, but the basic bond in polyethylene, the carbon-carbon bond, is there as well, ＂she explains, ＂The wax worm evolved a method or system to break this bond. ＂

    Jennifer DeBruyn, a microbiologist at the University of Tennessee, who was not involved in the study, says it is not surprising that such worms can break down polyethylene. But compared with previous studies, she finds the speed of breaking down in this one exciting. The next step, DeBruyn says, will be to identify the cause of the breakdown. Is it an enzyme produced by the worm itself or by its gut microbes(肠道微生物)?

    Bertocchini agrees and hopes her team's findings might one day help employ the enzyme to break down plastics in landfills. But she expects using the chemical in some kind of industrial process — not simply ＂millions of worms thrown on top of the plastic.＂

    It's OK to say you've never heard of grime (伦敦地下音乐) - unless you're from the UK. That's because this music type was invented in the UK in the early 2000s.

    To someone who's not familiar with underground music culture, it's easy to get confused between hip-hop and grime since they are both noisy. And many people didn't bother to tell them apart，until earlier this month when grime stars like Stormzy and J Hus led this year's Mobo – “music of black origin”, an award in the UK. Just like UK electronic music and hip-hop, from which grime drew influence, it mostly reflects the thoughts of young people. But different from hip-hop, grime singers sing in dialects with strong accents, giving a special flavor to their songs.

    Lady Leshurr，known as the “Grime Queen”, said that she once tried to hide her accent, as she didn't want people to judge her. But one day, she realized that she didn't need to change herself just to please others. And there's no doubt that this is the soul of grime music: be yourself.

    Grime has challenged modem music in its production beauty and its expressions. Also different from the hip-hop culture, which usually focuses on being rich, grime singers pay more attention to social phenomena like those who suffer from disasters and the gap between the rich and poor.

    Although still quite a young music type, grime seems to be getting loved by more and more people. In 2016, the English grime artist Skepta won the Mercury Prize with his album Konnichiwa, beating big names like David Bowie and Radiohead.

    However, no matter whether grime is one day accepted widely or not, one thing is for sure: in grime, singers always stay true to themselves.

    Have you ever wondered why birds sing? Maybe you thought that they were just happy. After all, you probably sing or whistle when you are happy.

    Some scientists believe that birds do sing some of the time just because they are happy. However, they sing most of the time for a very different reason. Their singing is actually a warning to other birds to stay out of their territory.

    Do you know what a "territory" is? A territory is an area that an animal ,usually the male, claims(声称)as its own .Only he and his family are welcome there. No other families of the same species(物种)are welcome. Your yard and house are your territory where only your family and friends are welcome. If a stranger should enter your territory and threaten you, you might shout. Probably this would be enough to frighten him away.

    If so, you have actually scared the stranger away without having to fight him. A bird does the same thing. But he expects an outsider almost any time ,especially at nesting(筑巢)season. So he is screaming all the time, whether he can see an outsider or not. This screaming is what we call a bird's song, and it is usually enough to keep an outsider away.

    Birds sing loudest in the spring when they are trying to attract a mate and warn others not to enter the territory of theirs.

    You can see that birds have a language of their own. Most of it has to do with attracting mates and setting up territories.

Three Japanese tourists taking a holiday in Australia got stuck when their GPS told them they could drive from the mainland to an island, failing to mention the 15 kilometres of water and mud in between.

As they drove their hired car from Moreton Bay to nearby North Stradbroke Island, they started to notice the firm surface they were driving on giving way to the well­known bay mud. However, being confident that their GPS would direct them to a road soon, they decided to drive on, managing to travel around 500 metres before their car was up to its tires in mud. To make matters worse, the tide (潮汐) started to come in and soon forced them to seek help and abandon the vehicle. Just four hours later the car was trapped in two metres of water—to the great amusement of onlookers on the shore and passengers on passing boats and ferries.

Yuzu Noda, 21, said she was listening to the GPS and "it told us we could drive down there. It kept saying it would navigate (导航) US to a road. But we got stuck… there's lots of mud". She and her travel companions Tomonari Saeki, 22, and Keita Osada, 21, instead had to give up their plans for a day trip to the island and headed back to the Gold Coast of a lift from the RACQ tow truck (吊车) driver who was called to the trapped car. No such luck for the hired car, though—after assessing the situation, no attempt was made to recover it. The students from Tokyo, who are due to return home tomorrow, said the experience would not put them off returning to Australia for another visit. Mr Tomonari said, "It has rained every day on our six day holiday. Hopefully next time we come back it will be sunny. "

The car was covered by insurance, but the tourists will have to pay up to about $1,500 in extra charges.

The brain-training app trains people to tap on images of healthy foods but to stop when they see unhealthy snacks, creating a link between these foods and stops. The new study, by the universities of Exeter and Helsinki, found that playing the game about once a day for a month led to an average one-point reduction of junk food consumption.

Generally, people who used the app more also reported great changes in their food intake. One app user wrote, "Really useful. I used to eat junk food two to four times a week and I have reduced this to once a week after using the app regularly for a month. My desire for junk food has been reduced greatly and I no longer eat in the evening mindlessly."

The study used the app's usage data, and the app regularly asked questions about how often users eat certain food, along with other information such as their age and weight. The findings suggested that using the app regularly was linked with big changes in eating habits.

The app is free and it only takes about four minutes per day, so it's something people can do not just at home but at work and elsewhere. "From our results it seems important that you do the training at regular times and don't just stop. Therefore, keep it interesting, so you won't get bored with it. Personalize the app as much as possible and pick the food that you find really hard to resist," said Natalia Lawrence, a professor of the University of Exeter.

The researchers stressed that their findings should be further proved, because there was no comparison group and other factors____(such as the possibility that people who did more training were also more motivated to lose weight) could play a part in the results.