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．

    Many wild animals, such as pandas, are in d{#blank#}1{#/blank#}. Often there is not e{#blank#}2{#/blank#} land or forests, so the animals do not have a safe place to live.

    There are only about 1,600 pandas in the wild today. Pandas do not have many babies, and baby pandas often d{#blank#}3{#/blank#}. The situation is getting more and more difficult. We need to p{#blank#}4{#/blank#} them.

    The government is s{#blank#}5{#/blank#} up nature parks and the pandas live in peace there.

    Our life will be different from nowadays with robots appearing in our homes. So what will the future be like? Here are some students' ideas.

    Would you like to go to the zoo at night? Last month, Shanghai Wild Animal Park opened its night safari(夜间观赏)for the first time. You can see animals in the dark. Some animals enjoy the night—they are nocturnal(夜行的)animals. Who are they?

    Height is just one of the thousands of features that your genes(基因) decide. In fact, because you have two parents, your genes provide you a height that usually lands somewhere between the height of each parent. If both your parents are tall, then most probably you will be tall, too. But if you have questions about how tall you're going to be, ask your doctor if he or she can help you find it out.

    But genes don't decide everything. For example, eating an unhealthy diet can keep you from growing to your full potential(潜力). Getting plenty of sleep and enough exercise will help you grow to the expected height.

    No doubt you're wondering how fast you should grow. There's no perfect or right answer. Generally speaking, kids grow about two inches(six centimeters) a year between age 3 and the time when they start puberty(青春期).

    Your doctor will know how your growth has been going over the years, how you've been growing up to this point, and what other changes your body may be going through.

    Don't be scared if you seem to have grown a lot in a very short time. Everyone has a growth spurt(高峰) during puberty. The age for starting puberty is about 10 for girls and about 11 for boys. But it can be earlier or later-between 7 and 13 for girls and between 9 and 15 for boys.

    You'll usually begin to notice that you're growing faster about a year or so after your body starts to show the first changes of puberty.

    Beauty sleep is a real thing, researches have shown that people who have enough sleep look more attractive (有魅力的) to others.

    A few bad nights are enough to make a person look especially "more ugly", their sleep experiments show.

    The researchers asked 25 university students to join in their sleep experiment. They were asked to get a good night's sleep for two nights.

    A week later, they were asked to sleep for only four hour every night for two nights in a row. The researchers took make—up free (素颜) photos of the volunteers after both the good and the bad sleep.

    Next, they asked 122 strangers to have a look at the photos and judge (评价) them on attractiveness, health, and sleepiness, as well as asking them: "How much would you like to make friends with this person in the picture?"

    The strangers were good at judging whether the person they were looking at was tired, and if he was sleepy, his attractiveness score would be low.

    The strangers also said they wouldn't want to socialize with the tired students. The researchers say this is natural for people. An unhealthy-looking face makes people run away. In other words, people don't want to hang around with people who might be ill.

    Dr Brewer, an expert at the University of Liverpool said: "Judgment of attractiveness is often unconscious (无意识的), but we all do it, and we are able to judge on even something small like whether someone looks tired or unhealthy. This study is a good reminder of how important sleep is to us."