The Renaissance，considered by modern scholars to have been the time between 1,300 and 1,600，was a period of European history when many new inventions and beliefs came into being.

    The Renaissance is traced back to rich Italian cities such as Florence，Milan，and Venice.In these cities businessmen started to spend their extra money on things like painting and education，and to consider new techniques of banking and systems of government.A new type of scholar，the humanist(人文主义者)arose.Humanism was concerned with humankind and culture.Latin and Greek，literature and philosophy，music and mathematics were among the subjects humanists studied.

    The Renaissance gave rise to new forms of painting and  sculpture.During  the  Renaissance，artists were no longer regarded as mere artisans(工匠)．Many artists drew on mathematics in order to become more accurate in their measurements(度量)and to make sure an object was presented in realistic proportions.They also studied the way light hits objects and the ways our eyes perceive it.A new kind of paint，called oil paint，was invented.

    The Renaissance affected all of the society.Many people became interested in politics，and the world outside their towns.They became explorers，businessmen，etc.The effect on religion was especially strong.In the Middle Ages people were primarily concerned with serving the church and getting to heaven.But the increase in arts  and education gave  people things to look forward to in life，and made them lose interest in the church.

    The  Renaissance  produced  many  great minds.Leonardo da Vinci was one of the greatest，although he was not regarded that way at the time.Among his many works of art were Mona Lisa and The Last Supper.He is also regarded as a great inventor，and is credited for coming up with the idea of the helicopter.

    When you're having a hard time with your homework or when you're preparing for your term paper, these student-focused websites can help you with just about anything you need. The key to getting the most out of these online resources is to know how they can best be used to your advantage.

Facebook

    Although Facebook can be one of your biggest time-wasters and distractions when you are supposed to be getting work done, it can also be one of your most valuable resources. Most of your classmates will probably have a Facebook account, so anyone you need to connect with about a class you missed or about a problem is usually just a few clicks away.

SparkNotes

    With a free library of history timeline, philosophy study guides and library summaries, SparkNotes has covered just about any reading-related jam you find yourself in. Just run a search for the book, play, or short summary of the material you are supposed to read.

Amazon.com

    Do you finish every term with many expensive textbooks you will never open again? Instead of letting the money spent go to waste, get back some of your cash by selling your books on Amazon.

RateMyProfessors.com

    Choosing new classes can sometimes be like trying to pick out your clothes in the dark, a total guessing game. Which teacher gives out the hardest problem sets? How much homework will that history professor give you every week? At RateMyProfessors.com, students all over the country rate their professors on quality, helpfulness, and how hard their classes are.

 Wikipedia

    While Wikipedia isn't aimed specifically at students, it is difficult to think of another website that does more to reduce the pain of paper writing and researching. Wikipedia gives you a quick way to find sources and get the details of almost any topic you need to research — all without walking to the library.

    Competition occurs naturally between living beings which co-exist in the same environment. In modern society there is a great deal of argument about competition. Some value it highly, believing that it is responsible for social progress and prosperity(繁荣). Others say that competition is bad ;that it sets one person against another ;that it leads to unfriendly relationship between people.

    I have taught many children who held the belief that their self worth relied on how well they performed at tennis and other skills. For them playing well and winning are often life and death affairs. In their single minded pursuit(追求)of success, the development of many other human qualities is sadly forgotten.

    However, while some seem to be lost in the desire to succeed, others take an opposite attitude. In a culture which values only the winner and pays no attention to the ordinary players, they strongly blame competition. Among the most vocal are youngsters who have suffered under competitive pressures from their parents or society.

    Teaching these young people, I often observe in them a desire to fail. They seem to seek failure by not trying to win or achieve success. By not trying, they always have an excuse :”I may have lost, but it doesn't matter because I really didn't try.” What is not usually admitted by themselves is the belief that if they had really tried and lost, that would mean a lot. Such a loss would be a measure of their worth. Clearly, this belief is the same as that of the true competitors who try to prove them-selves. Both are based on the mistaken belief that one's self respect relies on how well one performs in comparison with others. Both are afraid of not being valued. Only as this basic and often troublesome fear begins to dissolve (缓解) can we discover a new meaning in competition.

Dear Alcohol,

    You've been around forever. I can remember all the pain you've caused me.

    Do you remember the night when you almost took my father's life? I do. He loves you. Sometimes I think he loves you more than he loves me. He's addicted to you, to the way you promise to rid him of his problems only to cause more of them. You just sat back and laughed as his car went turning through the street, crashing into two other cars. He wasn't the only one badly hurt by you that night.

    Do you remember the night of my first high school party? My friends were intrigued by you. They treated you as if they were never going to see you again, drinking all of you that they could. I spent two hours that night helping my friends who had fallen head over heels for you. “I'm so embarrassed,” they said as I held their hair back so that they could throw up. “I'm sorry,” they said when I called taxis for them, walking them out and paying the driver in advance. “This won't happen again,” they said as they were sent to the hospital to have their stomachs pumped. Two 15-year-old girls slept in hospital beds that night due to you.

    Do you remember the night when you took advantage of my 17-year-old neighbor who had to drive to pick up his sister from her dance lesson? Do you know how we all felt when he hit another car head-on and killed two people in the other car? He died the next morning, too. His sister walked home from her dance lesson, and passed police cars and a crowd of people gathering on the sidewalk just two blocks away from the dance studio. She didn't realize her brother was among them at all. She never saw him again. And it was all your fault.

    I wish you'd walk out of my life forever. I don't want anything to do with you. Look at all the pain you've caused. Sure, you've made people happy too from time to time. But the damage you've caused in the lives of millions is not excusable. Stop attracting the people I love! Stop hurting me, please!

Sincerely,

Me

    There's a new frontier in 3D printing that's beginning to come into focus: food. Recent development has made possible machines that print, cook, and serve foods on a mass scale. And the industry isn't stopping there.

     Food production

    With a 3D printer, a cook can print complicated chocolate sculptures and beautiful pieces for decoration on a wedding cake. Not everybody can do that — it takes years of experience, but a printer makes it easy. A restaurant in Spain uses a Foodini to "re-create forms and pieces" of food that are "exactly the same," freeing cooks to complete other tasks. In another restaurant, all of the dishes and desserts it serves are 3D-printed, rather than farm to table.

    Sustainability(可持续性)

    The global population is expected to grow to 9.6 billion by 2050, and some analysts estimate that food production will need to be raised by 50 percent to maintain current levels. Sustainability is becoming a necessity. 3D food printing could probably contribute to the solution. Some experts believe printers could use hydrocolloids (水解胶体) from plentiful renewables like algae(藻类) and grass to replace the familiar ingredients(烹饪原料). 3D printing can reduce fuel use and emissions. Grocery stores of the future might stock "food" that lasts years on end, freeing up shelf space and reducing transportation and storage requirements.

    Nutrition

    Future 3D food printers could make processed food healthier. Hod Lipson, a professor at Columbia University, said, "Food printing could allow consumers to print food with customized nutritional content, like vitamins. So instead of eating a piece of yesterday's bread from the supermarket, you'd eat something baked just for you on demand."

    Challenges

    Despite recent advancements in 3D food printing, the industry has many challenges to overcome. Currently, most ingredients must be changed to a paste(糊状物) before a printer can use them, and the printing process is quite time-consuming, because ingredients interact with each other in very complex ways. On top of that, most of the 3D food printers now are restricted to dry ingredients, because meat and milk products may easily go bad. Some experts are skeptical about 3D food printers, believing they are better suited for fast food restaurants than homes and high-end restaurants.

    Happy, angry, amazed—these are some of the emotions we like to express these days when we're sending a message on our smart phones! That's why many of us now add little pictures to our texts to brighten up someone's mobile screen but we're also using them as a quick way of telling someone how we're feeling. Yes, emojis (表情符号) have become a popular tool for communication.

    The emoji was first invented in Japan in the late 1990s and the word "emoji" comes from the Japanese words for "picture" and "character". The number of different images has greatly increased since then and now we have a picture for nearly every mood or situation.

    Why are emojis widely used today? Professor Vyv Evans says, "Increasingly, what we're finding is that digital communication is replacing face-to-face talk in some ways. One of the reasons why emojis are so interesting is that they really do enable us to express our emotional selves much more effectively."

    Another advantage of emojis is that they are an international language—they don't use words but tell a message with pictures so they can be easily understood whatever your native language is.

    But as linguist (语言学家) Neil Cohn says, "To many, emojis are an exciting evolution (进化) of the way we communicate; but to others, they are linguistic Armageddon." It does show by using emojis, there is a lot more to our communication than words alone, but does this also mean that the traditional writing will die out one day?