First Lady Michelle Obama is a big fan of volunteering. Volunteering means working for free to help someone else. Mrs. Obama says volunteering is very important. “It should be part of everyone's life,” she says.

    Many teens agree. They say that helping others feels great and makes a difference. These days, more teens volunteer than work for pay. Teens clean up parks, walk dogs at animal shelters, visit the elderly and more.

    Some cities —including Seattle, Chicago, and Washington, D.C. —require high school students to volunteer. Students must volunteer in order to graduate. The student volunteers learn new skills and help their communities.

    Many parents are in favor of the idea —they say volunteering helps teens build job skills. But most teens don't want to be forced to volunteer. They say they are busy. And they say volunteering is only fun if it's a choice.

Read both sides of the debate and decide.

YES

Volunteering can help teens get into college or get a job.

Many cities and towns need help. Volunteers can help keep important programs going.

Not all teens will volunteer if it isn' t required. Schools should require students to do all they can to get ready for adult life.

NO

Most teens are already very busy with classes, homework, jobs and sports. Forcing them to do more isn't fair.

It should be up to each person. Helping out doesn't feel as good if you have to do it.

Finding a volunteer job isn't always easy. Students shouldn't be kept from graduating because of something they can't control.

    We brush our teeth daily, but do you know everything you need to know about dental care and hygiene? Believe it or not, there is a lot more than most people realize. Luckily, here are several apps that can help you.

●Brush DJ

    You should brush your teeth for full two minutes as recommended by dentists, but that time can be difficult to judge. Many recommend you listen to music, because many songs are just around two minutes in length. Brush DJ has loads of great tunes that will get you into the two­minute habit. There are both songs to listen to, and videos to watch, and you'll find a variety of awesome tunes.

●Orasphere

    It's recommended that Orasphere videos be used by dentists for their patients, so they can learn about procedures. Those who do use these videos say that the software can greatly decrease the amount of time it takes to explain procedures to patients.

●American Dental Association(ADA)

    Everything you ever wanted to know about your teeth, and then some, can be found on the American Dental Association(ADA) website. You'll find loads of great articles that have the latest news about dentistry（牙科）. Those interested in dental careers will find plenty of information to head them in the right direction, and there's even a section devoted to public dental programs, including Give Kids a Smile and Fluoride in Water.

●DDS GP

    Here is more presentation software that explains all types of dental procedures. This is helpful for dentists to have, because they can better explain procedures to their patients.

●Dentistry IQ

    You can find information for dentists, hygienists, assistants, office managers, and more at Dentistry IQ. You can also get information about new products, clinical practices, and much more. In addition, you can learn about career opportunities, the most recent practices, and a whole lot more.

    The human-caused rise in CO₂ hasn't yet reached its full warming effect, owing to the considerable delay in its impact on ocean temperature. There is still another 0.5^oC of so of warming to occur over the coming decades based on the current concentrations（浓度）of CO₂ in the atmosphere, and far more warming beyond that if CO₂ concentrations continue to rise greatly with the business-as-usual burning of fossil oil. To improve the situation, the world needs to shift firmly from coal, oil and gas to renewable energy by around 2050 and from cutting down trees to planting trees and restoring degraded lands.

    So why do human begins keep dashing in a stupid way ahead, toward certain tragedy?

    The main reason is that our political institutions and giant corporations intentionally ignore the rising dangers and damage.   ①    Managing a major company is about maximizing shareholder value, not about telling the truth or avoiding great harm to the planet. Profit -seeking investors own the major media, or at least influence them through their advertising purchases. Thus, a small yet very powerful group keeps the fossil-fuel-based energy system at growing dangers to the rest of humanity today and in the future.

    We need a new kind of politics that starts with a clear goal: environmental safety for the planet's people, by fulfilling the Paris agreement, protecting biodiversity, and cutting pollution, which kills millions each years.   ②    The new politics will listen to scientific and technological experts, not self-interested business leaders and politicians.

       ③    Such a politics is possible. In fact, the public longs for it. A large majority of the American people,for example, want to fight global warming, stay in the Paris climate agreement, and support renewable（可更新的）energy. Yet, as long as a narrow and ignorant elite（精英）judges Americans and the rest of human beings to wander aimlessly in the political desert, the more likely it is that we will end up in a wasteland from which there will be no escape.  ④   

    They say the average person makes 35, 000 decisions a day. Yet in her new book, How Woman Decide, Therese Huston explores a widespread phenomenon that many women fail to notice. "There's a huge double standard when it comes to how men and women are viewed as decision﹣makers," explains Therese, a psychologist from Seattle University. Therese decided to write the book after looking at her bookshelf: At one end, there were bestselling books about how to be a clever decision﹣maker ﹣ all written by men and featuring interviews with men like athletes. At the other end were books aimed at women on gaining leadership skills and confidence.

    "Once those women are at the table, will their decisions be taken as seriously as men's？" Therese wondered. "Men are respected as decision﹣makers more than women, especially in the workplace, largely because there's this cultural belief that women are unable to make smart choices at work. "

    So, Therese set out to pick apart the stereotypes（固有印象）to see what scientific research had found. "Scientific research shows that men and women struggle with decision-making equally. The only disadvantage I found was that during the teenage years-teenage girls are more indecisive than teenage boys. Otherwise, there's little difference between the genders（性别）.

    However, there are some differences. "Women are more collaborative（协作的）, "says Therese. "A female boss is more likely to ask the opinions of those around her when making a choice. Women ask for input, which helps make better decisions. However, this is often seen as a weakness rather than a strength.

    Therese also found that during times of stress, men and women make different choices, and the outcomes are often better when women are involved.

    Study after study backs this view up. Neuroscientists Mara Mather and Nicole Lighthall from the University of Southern California studied the way men and women make decisions and found that in times of stress, they react very differently.

    During their study, which involved playing a virtual gambling（赌博）game, they found that when the females became stressed, they made smart decisions ﹣ quitting while they were ahead or taking safe bets. But when the men became stressed, they did the opposite, risking everything for a slim chance of a big win.

    The Broadcom MASTERS competition aims to find a balance between celebrating individual accomplishments and acknowledging that science seldom happens alone. The competition takes off when students from around the country are teamed up and have to solve a series of hands—on challenges in the spotlight.

    Nowadays, kids are fed with “the myth of the lone scientist”, so placing such challenges in the middle school period has a huge potential for impact. The focus on teambuilding skills gets students excited before more fears and stereotypes(成见)set in.

    The initial pool of qualified students comes from the participants in nation-wide science fairs. Those who score in the top 10％(about 10, 000 kids)have the qualification to apply. The judges select the top 300 young scientists, and that group is finally narrowed to 30 finalists.

    Selection at this stage is clearly an honor in itself, but it counts as step one for the finalists. They are then flown to Washington, D. C. and placed into teams of five for the hands-on part of the competition. Each team is made up of students with different talents and skills, including academic focus and experience.

    Unlike the science fairs, where most of the work takes place behind the scenes and students share a polished outcome, the hands-on challenges create a space where the work is the competition itself. The students take up a range of challenges in science, technology, engineering, math and so on. Each of the challenges will need the insight and skills of multiple team members.

    Judges observing the challenges aren't just looking for outcomes but also for leadership, teamwork and problem solving.

    The Broadcom MASTERS attracts increasing numbers of passionate and talented young people who are eager to take part in a program that helps them grow as scientists, engineers and inventors. It lets the students experience a sense of coming together with true peers. More importantly, it provides them with new skills to tackle future challenges.

    Nowadays, most people have a device that features artificial intelligence (AI), with the likes of Siri always there to greet us with a friendly voice.

    But Microsoft's XiaoIce is different. Launched in 2014 for the Chinese market, "she" has a creative advantage over her competitors. While most AI assistants simply read out information they get online, XiaoIce has a "realness" that the others are short of. Indeed, if you asked nicely, she could read you a poem from the weekly column in China Daily.

    The newspaper has been printing XiaoIce's self-penned poetry each week since Aug 19, taken from her own book of poems, The Sunlight that Lost the Glass Window.

    To turn XiaoIce into a master of poetry, Microsoft scientists "fed" her the works of over 500 influential modern poets, reported China Daily.

    This led to her figuring out a writing style of her own and creating over 70,000 original poems. Most of the poems are so comparable to those written by humans that they cannot be easily distinguished, and XiaoIce's book even got good feedback from experts.

    "XiaoIce's work carries a strange taste. The more you chew on it, the more interesting it becomes," Scholar Zhang, a literature professor at the Nanjing University of Science and Technology, told China Daily.

    However, it seems not everyone is a fan. "The poems dissatisfied me with their slippery tone and rhythm. The sentences were aimless, lacking the inner logic for emotional expression," Yunnan-based poet Yu told China Youth Daily. This isn't the first AI to attempt poetry. Last year, Google's Parsey McParseface made some poems of its own, although they were branded "wrongly" by reviewers. While it seems like AI is becoming more "intelligent" and less "artificial" all the time, when it comes to creativity, perhaps this is one job that software should leave to us humans.