You've heard of 3D printing from newspaper and TV programs．It can “print”in plastic，metal，nylon，and over a hundred other materials.3D printing technology has been around since the 1980s，it was not widely used until the early 2010s．The first working 3D printer was created in 1984 by Chuck Hull．

3D printers use many different types of technologies，but they all share one thing in common：they create a three—dimensional(维度的)object by building it layer(层)，by continuing layer, until the whole object is completed．Imagine a baker(面包师)lay down each layer one at a time until the whole cake is formed.3D printing is somewhat similar， but just a bit stricter．How can 3D printers work so well? The most important thing a program，a 3D printer also needs to have instructions for what to print from a computer．It needs a file as well．The file which is a Computer Aided Design (CAD)paper is created with the use of a 3D modeling program．The program creates a paper that is sent to the 3D printer. Along the way，software pieces the design into hundreds，or more likely thousands of layers．The 3D printer builds up one layer at a time，from the bottom to the top，until the object is done．

    3D printings can be used for making many kinds of things such as machine parts， daily life objects，even human organs(器官)using a person's own cells．

Nowadays, Marc．Dillon founds a project which deals with many world famous paintings like Leonardo da Vinci's Mona Lisa, Van Gogh's Sunflower with 3D technology．This project helps the blind people enjoy the fantastic art through touching．In order to provide a good user experience，these 3D paintings have special instruments which can tell people what they touch．

    Soon computers and other machines will be able to remember you by looking at your eyes! The program works because everyone's eyes are different. So in the future you won't have to remember the number of your credit card when you want to use a machine or take money out of a bank. You'll just have to look at the machine and it will be able to tell who you are.

    The eye-recognition（眼睛识别）program has already been tested in shops and banks in the USA, Britain, Spain, Italy and Turkey. Soon this technology will take the place of all other ways of finding out who people are.

    Eye-recognition is a course of recognizing iris（虹膜）, which includes the following steps. First, a kind of machine needs to collect different examples of one's iris from his eyes and store them. Second, when this person goes to the bank to take out money, this machine will have iris feature extraction（采集）. Then, this machine will compare the examples kept in it with iris feature extraction. Once the examples and the feature extraction are the same, this person will be identified, and he will take out the money from the bank successfully.

    However, scientists are also working on other systems. Machines will soon be able to know you from the shape of your face or hand or even your smell! We already have machines that can tell who you are from your voice or the mark made by your finger.

    Eye-recognition is better than other kinds because your eyes don't change as you get older, and don't get dirty like hands or fingers, and even twins have different eyes. So the eye-recognition program can be up to 94% correct, depending on how good the technology is. However, some other programs may only be 51% correct now. In Britain, it was found that 91% of people who had tried it said that they liked the idea of eye-recognition.

    In the future your computer will be looking you in the eye. So smile!

    If your pen broke at school today, what would you do? You would go to a shop and buy a new one. What if you could simply print out a real, working pen with your 3-D printer without leaving your room?

    Ten years ago people could only see 3-D printing in science fiction movies. But now 3-D printing is here and it's bringing big changes.

    Unlike normal printing that can only copy a 2-D picture with ink. 3-D printing can build almost anything made from material. The printer layers(分层) the material in different shapes to create the object you want to be copied.

    The 3-D printer has been used to make many different things. People have made cups, cars and even an airplane with it. Doctors have been using 3-D printers for several years. People's nervous systems(系统) have been printed out in 3-D form in medical research. Some body parts have been printed and used in hospital. Several months ago, doctors used a 3-D printer to rebuild the face of a person who had a bad accident. In the future, it is expected that the printer will make human organs(器官)to save more lives.

    However there are drawbacks to the printer. At the moment, printing can be quite slow and it's still rather expensive. The average(平均的) price of a household printer is around $1,700, not including the cost of the materials.

    But as the technology develops, it shouldn't be long before disadvantages are improved. Only time will tell where this new technology will take us.

With our already busy lives, finding time to exercise can be impossible. So maybe it would help if there was ‘a best time' to exercise.

There are clear benefits to exercising in the morning. Many of us have more free time than later in the day, and it may be easier for us to keep a morning plan. A study found that people could sleep better when they exercised in the morning or had the physical activity during the whole day. Exercising on an empty stomach（空腹）before breakfast could also have less fat（脂肪）and keep healthier.

So, good news for early birds, but what if you're not a morning person? Working out in the afternoon or evening is also good, but different. For example, your body's ability reaches the highest level in the afternoon, according to a 2010 study. Also, in the afternoon and evening, your mind is the quickest, and your heart rate and blood（血）pressure are lowest, and you aren't getting hurt（受伤）easily when exercising.

But can this happen? Deciding on if you are a man or a woman? Our bodies are different, after all, so the best time to exercise may be different too. Want to reduce（降低）your blood pressure and you are a woman? Exercise in the morning. Want to improve your heart health and you are a man? Evening is better for you. But, a 2022 study found that it's both OK for them to exercise at either time of day.

So what time is best? It seems the answer is: whatever time is best for you!

Hard-working horses have always been man's best friends, but the playful pony is a kid's best friend.

A pony is a small horse. Like horses, they have a lot of hair. The most well-known is the small Shetland pony, only as tall as a six-year-old child! Shetland ponies can pull twice their own weight (重量), with only their thick hair to protect them from the cold.

Ponies eat grass, oats and bran (燕麦和糠) and they also love carrots and apples. They don't eat meat, ponies can sleep both lying down and standing up.

They are very playful, which is why they get on so well with children! They are happy to hang with their friends and go for rides. They enjoy having fun as much as their riders.

Like you and your friends, every pony is different. Some are quiet and some are cheeky (嬉皮笑脸的). Some are hard-working and others can be a bit lazy. Ponies are sensitive and often try to cheer you up when you feel sad. Just like you, they prefer to be spoken to kindly rather than shouted at!

A pony makes a great playmate but remember that it is not a toy. It is a living animal that needs care and lots of loving attention. You have to learn how to feed and groom (刷洗) it every day, how to clean its feet so that they stay healthy, are they?

During this yearˈs Labour Day holiday, Yemeni (也门的) student Mohammed Saleh Ahmed and his Chinese friends visited Pingyao ancient city in Shanxi Province. They even experienced the ancient way of getting money in the {#blank#}1{#/blank#}(early) bank of China. 

"The historical relics (遗迹) in China's ancient cities have made me want to learn more about the {#blank#}2{#/blank#}(country) past, " Mohammed said. In recent years, tourism industries have developed quickly and these relics {#blank#}3{#/blank#}(become) new favourites of tourists. 

Xinzhou ancient city in Shanxi, {#blank#}4{#/blank#}a history of more than 1, 800 years, has over 500 stores and restaurants. During {#blank#}5{#/blank#}five-day holiday, Xinzhou ancient city received more than 400, 000 visitors. "My restaurant is always busy. During the peak season, the yard is crowded with tourists {#blank#}6{#/blank#}(wait) for dinner, " said Wang Guodong, a businessman who owns a restaurant in Xinzhou ancient city. 

Geng Yeqiang, an expert from Shanxi University, said that historical relics can form a cultural tourism circle during their protection and {#blank#}7{#/blank#}(develop). The process can increase local economic growth. The expert also said, "At the same time, relics protection organizations and the tourism organizations should work together{#blank#}8{#/blank#}(make) this economic model better. 

{#blank#}9{#/blank#}a modern city meets its old past, not only can the tourism be developed better, but the local culture and history can also {#blank#}10{#/blank#}(know) by more people.