Garbage or trash is a major kind of environmental pollution.Each person produces about 2kg of trash a day.We are making waste products faster than nature can break them down.And we are using up resources（资源）faster than they can be replaced（取代）.

    This adds up to trouble for the environment.Where does all that garbage go?What can be done to help dispose of（处理）garbage?How call we make less garbage?

    Garbage isn't just the smelly rotting fruits,vegetables or meat that we throw away in our homes.Those are only a small pan of all the stuff we throw away.We create other kinds of waste,in construction,mining and in our factories.

    Did you ever wonder what happens to your garbage?Most is burned or buried in landfills（垃圾填埋场）Less than a quarter of our waste is recycled.

    With a population of 1.3 billion（十亿）,garbage is a big problem for China.Chinese cities create around 148 million tons of garbage every year.The amount is growing at around 10 percent each year.

    Once we used about 3 billion plastic shopping bags every day in China.The result was a great waste of resources and serious pollution.So we did something about that.Now we use more cloth bags and shopping baskets when we shop.

    In the coming years China will build waste-to-energy plants in cities to clean up the garbage.But there's a lot more that needs to be done.And you can play a part.

    When we think about happiness, we usually think of something surprising and unexpected, a top great delight.

    For a child, happiness has a magic quality. I remember playing police and robbers in the woods, getting a speaking part in the school play. Of course, kids also experience lows, but their delight at tops of pleasure is easily seen, such as winning a race or getting a new bike.

    For teenagers, or people under 20, the idea of happiness changes. Suddenly it's conditional on such things as excitement, love, and popularity. I can still feel the pain of not being invited to a party that almost everyone else was going to. I also recall the great happiness of being invited at another event to dance with a very handsome young man.

    In adulthood the things that bring great joy — birth, love, marriage — also bring responsibility and the risk of loss. Love may not last; loved ones die. For adults, happiness is complex.

    My dictionary explains “happy” as “lucky” or “ fortunate”, but I think a better explanation of happiness is “ the ability to enjoy something”. The more we can enjoy what we have, the happier we are. It's easy for us not to notice the pleasure we get from loving and being loved, the company of friends, the freedom to love where we please, and even good health. Nowadays, with so many choices and much pleasure, we have turned happiness into one more thing we have. We think we own the right to have it, which makes us extremely unhappy. So we try hard to get it and consider it to be the same as wealth and success, without noticing that the people who have those things aren't necessarily happier.

    While happiness may be more complex for us, the answer is the same as ever. Happiness isn't about what happens to us. It's the ability to find a positive for every negative, and view a difficulty as a challenge. Don't be sad for what we don't have, but enjoy what we do possess.

    Thirteen-year-old American Jessica Goldstone wants to be a fashion designer when she finishes school. She thinks her designs would be more exciting than clothes bought from stores. But until this month, Jessica has never touched a sewing machine(缝纫机).

    After her first class, Jessica and six other girls aged 9 to 13 said that sewing was fun, cool and challenging.

    These students at Fabrics' Sew Fun class show that the sewing machine is becoming popular again.

    “There have been a lot of teens getting excited about sewing,” said a sewing company worker Donna Smith. “Some of them come from the Project Runway TV show,” she said. This TV show is an exciting weekly contest to make a great fashion designer. Every week one contestant (参赛者) fails the test and has to leave the contest.

    The number of people who joined sewing class summer camps grew by 10 percent this year. That's good news for companies that make sewing machines and publish sewing magazines. The Singer Sewing Company sold nearly 3 million sewing machines in the United States last year. This is about twice as many as in 1999.

    Sewing machines have been around for more than 150 years, but they have changed a lot since your grandmother was a girl.

    Spencer Carmel started sewing lessons after getting a sewing machine for her 11^th birthday. She has sewn a lot by hand, but she wants to make more difficult things. Spencer's class recently made hats.

    Another member of the class, Kelsey Oen, 9 years old, needed time to get used to her machine, but soon she could use it well. By the end of the class, Kelsey was happy and wearing her new hat.

Tour in the Museum

    Experts or folk scholars lead the tour in the museum and throw further light on certain exhibits. Lectures and interactive events will be held to discuss popular scientific topics. Two public themed lectures will be held every month, like "Unlock the Space Station" and "Looking into the Amazing Brain" etc.

    Fan Workshop

    The series of hands-on courses include "WEDO2.0 Robot", "First Step for Robot Design", "Get Creative with Lego", "Space Exploration" and "Science and Technology" etc. Through exploration, cooperation, creation and sharing, the workshop is set to interest students in science, engineering and mechanics.

    Everyone Can Code

    Based on Apple's Swift language and Swift Playgrounds, the courses, such as How an app is produced, Exploration into Face ID and Program for Dash robot are available to fuel teenagers' interest in programming and cultivate their logical thinking. The aim is get people to feel the fun in programming.

    Live Show

    Unlike the traditional teaching mode, a scientific show will present the scientific principles. The public is able to see the show as well as be in the show to feel the charm in a closer place. Fourteen topics are now available, including "the Power of Structure", "Voice and Music" and "Secret for a Polar Bear to Keep Warm".

    The Internet has opened up a whole new on-line world for us to meet, chat and go where we've never been before.

    But just as in face-to-face communication, there are some basic rules of behavior that should be followed when online. The basic rule is simple: treat others in the same way you would want to be treated. Imagine how you'd feel if you were in the other person's shoes.

    For anything you're about to send: ask yourself, "Would I say this to the person's face?" If the answer is no, rewrite and reread. Repeat the process till you feel sure that you'd feel comfortable saying the words to the person's face.

    If someone in the chat room is rude to you, your instinct is to fire back in the same manner. But try not to do so. You should either ignore the person, or use your chat software to block their messages. If it was caused by a disagreement with another member, try to fix the situation by politely discussing it. Remember to respect the beliefs and opinions of others in the chat room.

    Everyone was new to the network once. Offer advice when asked by newcomers, as they may not be sure what to do or how to communicate．When someone makes a mistake whether it's a stupid question or an unnecessarily long answer, be kind about it. If it's a small mistake, you may not need to say anything. Even if you feel strongly about it, think twice before saying anything. Having good manners yourself doesn't give you license to correct everyone else.

    If you do decide to tell someone about a mistake, point it out politely. At the same time, if you find you are wrong, be sure to correct yourself and apologize to those that you have offended.

    It is not polite to ask others personal questions such as their age, sex, and marital status. Unless you know the person very well, and you are both comfortable with sharing personal information, don't ask such questions.

    Artificial intelligence (AI) technology may soon be a useful tool for doctors. It may help them better understand and treat diseases like breast cancer in ways that were never before possible.

    Rishi Rawat teaches AI at the University of Southern California's (USC) Clinical Science Center in Los Angeles. He is part of a team of scientists who are researching how AI and machine learning can more easily recognize cancerous growths in the breast. Rawat provides information about cancer cells to a computer. He says this data helps the machine learn. “…You can put the data into them and they will learn the patterns and the pattern recognition that's important to making decisions.”

    David Agus is another USC researcher. He believes that “machines are not going to take the place of doctors.” He adds, “Computers will not treat patients, but they will help make certain decisions and look for things that the human brain can't recognize these patterns by itself.”

    Once a confirmed cancerous growth is removed, doctors still have to treat the patient to reduce the risk of cancer returning. The form of treatment depends on the kind of cancer. Currently, researchers take a thin piece of tissue, put it on a small piece of glass and add color to better see the cells. This process could take days or even longer. Scientists say artificial intelligence can do something better than just count cells. Through machine learning, it can recognize complex patterns, or structures, and learn how the cells are organized. The hope is that machines will soon be able to make a quick diagnosis（诊断）of cancer that is free of human mistakes.

    “All of a sudden, we have the computing power to really do it in real time...We couldn't have done this, we didn't have the computing power to do this several years ago, but now it's all changed.” Agus adds that the process could be done “for almost no cost in the developing world.” He says that having a large amount of information about patients is important for a machine to effectively do its job in medicine.

    A doctor faces a series of critical decisions every day. The best a doctor can do is to make those decisions as informed as possible. Some of them are still hard to make. A doctor can ask people of whom he values their opinions and that's it. Imagine discussing these with an AI system that is even more rational（理性的）than anyone else.

    The University of Southern California researchers are now only studying breast cancer. But doctors predict artificial intelligence will one day make a difference in all forms of cancer.