See a cellphone cover that you like on Taobao? Forget about placing an order, paying the bill online and waiting for days for it to be delivered to you. In the near future, you'll be able to get it in minutes just by hitting “print” on your computer.

    You might find it hard to believe that you could actually “print” an object like you would a picture. But it is not that hard to understand how it would work. Just as a traditional printer sprays ink onto paper line by line, modern 3D printers spread material onto a surface layer by layer, from the bottom to the top, gradually building up a shape.

    Instead of ink, the materials the 3D printer uses are mainly plastic, resin(树脂) and certain metals. The thinner each layer is—from a millimetre to less than the width of a hair—the smoother and finer the object will be.

    This may sound like a completely new technology, but the truth is that 3D printing has been around since the late 1980s. Back then, it was barely affordable for most people, so few knew about it.

    Last year, though, saw a big change in the 3D printing industry—printers became much cheaper. For example, 10 years ago a desktop 3D printer might have cost ￡20，000, while now they cost only about ￡1，000, according to the BBC.

    Taken out of the factory and introduced to more diverse and common uses, 3D printing can create just about anything you can think of—flutes , bikinis, jewelry, aircraft parts and even human organs. In fact, scientists from Cornell University in New York have just made an artificial ear using a 3D printer, according to Science Daily. The fake ear looks and acts exactly like a natural one.

    However, as 3D printing becomes more common, it may bring about certain problems—such as piracy. “Once you can download a coffee maker, or print out a new set of kitchen utensils (餐具) on your personal 3D printer, who will visit a retail  store again？” an expert in 3D printing told Forbes News. Even more frightening, what if anyone in the world could use a 3D printer to print out a fully functioning gun?

    Joanna Cole, born on August 11, 1944 in Newark, New Jersey, has been credited to be one of the most popular children's authors of all time. She has written over 250 books and is famous for writing one of the most popular children's book series. She knew as early as 5th grade that she was interested in writing and science. Cole has owed a large part of her passion to one of her elementary school teachers.

    Joanna Cole continued her education by attending the University of Massachusetts and Indiana. She would eventually earn a bachelor's degree in psychology from the City College of New York in 1967; after graduation Cole decided to take some education courses to become a librarian at a Brooklyn elementary school in 1967. Eventually, she would take jobs working for Newsweek, Seesaw book club.

    Cole's passion for writing and science was still alive and well during this time. In 197l she decided to write her first book, Cockroaches. She did some research and discovered there had never been a book written for children about cockroaches. So she thought she would be the first.

    Cole struck gold when she wrote the first Magic School Bus in 1985. The book would go on to be published the following year and quickly became book series and cartoon series due to its success.

    Cole continued to write both non-fiction and fiction books for children. She writes in a way that will hopefully inspire children to think like a scientist. She does this by writing ideas instead of just facts. She also tries to ask questions in her books that require children to think and discover the answers as they read. This creates an engaging experience for children, so it is no wonder why younger readers are hooked on her books.

    According to findings of a survey by Citi and Seventeen Magazine, nearly four out of five (almost 80 percent) college students work while attending college, with the average work load of 19 hours per week. But should college students work while at college? Many factors should be considered.

    One benefit of working while in college is that it can help build your resume, regardless of whether the job is in your field, according to an article at Scholarships.com. "If you're lucky enough to find a job that closely relates to your major, you could get a leg up on the rest of your class once you graduate, because you'll have more experience in your chosen field," according to the article.

    Perhaps the most compelling reason for working while earning a degree is the money. While it's unlikely to entirely finance your education through a part-time or full-time job, you can still make quite a dent(削减)in the college bill by working.

    But some students prefer not to work while earning a degree so they can focus on getting the best grades. It's true that you'll have more time to stay at school if you don't work, provided you use that time wisely. If you feel like even 10-15 hours a week of work will hurt your grades, then perhaps you should not consider working.

    Working a part-time or full-time job can take away time from social activities, according to a You University TV article. "Trying to balance a job and your college studies, and taking a job can cut down your time to hang out with friends," according to writer Dave Potts.

    In addition to missing out on hanging out with your friends, working during college could prevent you from attending a number of campus events, such as movies on the lawn or football games. While you may be able to land a job that's flexible, it seems unlikely they'll let you choose your own schedule.

    So should students work at college? The decision should be made on a case-by-case basis. Some students can also thrive in school while working, whereas others can't.

    Something very strange and mysterious was going on in Sesemann's house. Every morning, when the servants went downstairs, they found the front door wide open. During the first few days that this happened, every room and corner was searched in great alarm to see if anything had been stolen, but not a thing in the house had been touched. The door was doubly locked at night, and for further security the wooden bar was fastened across it; but it was no good – next morning the door again stood open. One servant even claimed he had seen a white figure standing at the top of the steps and then all in a minute it disappeared.

    Mr. Sesemann told his old friend, a doctor, what had happened in his house. That evening they decided to wait for the ghost. One o'clock struck. There was not a sound. Suddenly the doctor lifted his finger. "Hush! Don't you hear something?" They both listened, and they distinctly heard the bar softly pushed aside and then the key turned in the lock and the door opened. They stepped into the hall.

    "Who is there?" thundered the doctor in a voice that echoed through the hall, as the two men advanced with lights and weapons towards the figure. It turned and gave a low cry. There stood Heidi, with bare feet, staring with wild eyes and trembling from head to foot. The two men looked at one another in surprise. "Child, why did you come down here?" said Sesemann. White with terror, and hardly able to make her voice heard, Heidi answered, "I don't know." The doctor gently took the child by the hand upstairs.

    Then the doctor sat down besides her and asked her some questions in a kind voice. Later he went downstairs. "Sesemann," he said, "let me first tell you that the child is a sleep-walker; secondly, the child is consumed with homesickness. Something must be done at once."

    If you think American cooking means opening a package and throwing the contents into the microwave oven (微波炉), think again. On the one hand, it's true that many Americans have cold cereal for breakfast, sandwiches for lunch and instant (方便的) dinners. From busy homemakers to working people, many Americans enjoy the convenience of fast food that can be ready to serve in 10 minutes or less. On the other hand, many Americans realize the importance of cooking skills. Parents—especially mothers'—see the importance of training their children—especially daughter's. Most Americans think that there's nothing better than a good home-cooked meal. But with cooking, as with any other skill, good results don't happen by accident.

    Probably every cook has his or her own way of cooking. But there are some basic skills that most people follow. For example, baking is a main method of preparing food in America. For that reason, Americans would find it next to impossible to live without an oven. American cooks pay special attention to the balance of foods, too. In planning a big meal, they try to include meat, a few vegetables, some bread and often a dessert. They also like to make sure the meal is colorful. Having several different colors of food on the plate usually makes for a healthy meal.

    For those who need guidance in their cooking, or for those who have just run out of ideas, recipes are a great help. Recipes list all the ingredients for a dish (generally in the order used), the amount of each to use, and a description of how to put them together.

In choosing a friend,one should be very careful.A true friend can help you study.You can have fun together and make each other happy.Sometimes you will meet fair-weather friends(不能共患难的朋友).{#blank#}1{#/blank#}But when you are down,they will run away.How do I know when I have found a true friend?I look for certain qualities(品质) of character.

Above all else,I look for understanding in a friend.{#blank#}2{#/blank#}He is not quick to judge.Instead,he tries to learn from others.He puts himself in the other person's place,and he tries to think of ways to be helpful.He is also a good listener.

At the same time,a true friend is honest.He does not look for faults in others.{#blank#}3{#/blank#}In short,a true friend will try to understand me and accept me.

Another quality of a true friend is reliability(可靠性).I can always depend on a true friend.If he tells me he will meet me somewhere at a certain time,I can be sure that he will be there.{#blank#}4{#/blank#}That is to say,if I am in trouble,he will not run away from me.

There is a fourth quality that makes a friend special.{#blank#}5{#/blank#}We should enjoy our lives,and we would enjoy our friendship together.That is why I especially like friends who are fun to be with.A true friend likes the same things I like.We share experience and learn from each other.

A.He notices their good points.

B.A friend in need is a friend indeed.

C.Don't make friends who are not careful.

D.If I need a favor,he will do his best to help me.

E.A special friend is someone with whom we can have fun.

F.They will be with you as long as you have money or luck.

G.A true friend tries to understand how another person is feeling.