Are you carrying too much on your back at your back at school? I'm sure lots of children of your age will say “Yes”. Not only the students in China have this problem, but children in the United States also have heavy school bags.

    Doctors are starting to worry that younger and younger students are having back and neck problems as a result of school bags being too heavy for them.

    “It's hard for me to go upstairs with my bag because it's so heavy,” said Rick Hammond, an 11-year-old student in the US.

    Rick is among students who have common school bags with two straps（带子）to carry them, but many other students choose rolling（有滚轮的）bags.

    But even with rolling bags, getting up stairs and buses is still a problem for children. Many of them have hurt their backs and necks because of the heavy school bags.

    But how much is too much? Doctors say students should carry no more than 10% to 15% of their own body weight.

    Scout Batch, a back doctor, said children under Grade 4 should stay with 10%. But it is also important that older children don't stay with over 15%, because their bodies are still growing.

    “Children are losing their balance and falling down with their school bags,” he said.

    Parents and teachers are starting to tell children to only take home library books they will be reading that night. Some teachers are using pieces of paper or thin workbooks for students to take home.

    One of the best answers is, as some children said, to have no homework at all!

    I was selfish as a teenager. I usually spent my time thinking about myself and taking care of my own needs. I let my older brother do most of the work around the house until he left for college. I let my mom and dad worry about our bills and problems while I read books, played, and lost myself in my own imagination. This didn't change even when I went to college either. I studied hard but only to make my own life better. Even when I started to explore my faith, it was only to increase my own happiness.

    I married after graduation and decided to start a family. Of course, I had no idea what hard knocks reality had in store for my selfish soul. Soon I found myself unemployed, deeply in debt, and with a new baby on the way. l found out that life has little sympathy for spoiled people. In fact, all of the struggles I was going through were beating the selfishness slowly out of me.

    Still, I didn't give up on happiness. I knew that there must be a way to find it. I finally realized, however, that it had to include more than just my own needs, wants, and desires. The answer began to make itself clear one night shortly after my baby boy was born. I got a bottle and held him in my arms. As I was feeding him I looked down and saw his big, innocent, trusting eyes. I smiled and talked to him. Then he smiled and I could feel my heart growing, expanding with love. I felt such peace and joy. At that moment I had a hint of the truth: it is by growing our hearts with love that we find our happiness.

    Carolyn Arends wrote: "The more people you let into your heart, the bigger your heart gets. The more love you get, the more love you have to give. It just keeps growing." So, keep loving, keep living and keep caring. Keep growing your heart today, tomorrow, and always.

    Why don't quiet carriages work, and how might they be make to? Quiet carriages on trains are a nice idea: travelers voluntarily make their phones silent, turn stereos off and keep chatter to a minimum. However, in reality, there is usually at least one silly babbler (喋喋不休的人) to break the silence.

    A couple of problems prevent peaceful trips. First, there is a sorting problem: some passengers end up in the quiet carriage by accident and are not aware of the rules. Second, there is a commitment problem: noise is sometimes made by travelers who choose the quiet carriage but find an important call hard to ignore.

    The train operators are trying to find answers. Trains in Queensland Australia, are having permanent signs added to show exactly what is expected; a British operator has invested in some technology to prevent phone calls.

    Microeconomics suggests another approach. Fining people for making a noise would surely dissuade (劝阻) the polluter and is a neat solution in theory, but it requires costly monitoring and enforcement. Another way would be to use prices to separate quiet and noisy passengers—in effect, creating a market for silence. A simple idea would be to sell access to the quiet carriage as an optional extra when the ticket is bought. Making the quiet coach both an active choice and a costly one would dissuade many of those who don't value a peaceful ride.

    Charging may also solve the commitment problem. This is particularly tricky, as attitudes to noise can change during the journey. Some passengers would pay the quiet premium but still chatter away when some vital news arrives. Schemes that reward the silent—a rating system among fellow passengers, for example—could help. The idea is that losing your hard-won reputation offsets the short-term gain from using the phone. But such a system also fails the simplicity test.

    A 2010 book by George Akerlof and Rachel Kranton argues that "norms"—feelings about how everyone should behave—also play a role in decision-making. Charging a price, even if just a token amount, means the quiet carriage becomes a service that fellow passengers have bought, not just a preference they have expressed. Perhaps different norms would come into play, encouraging calm. If not, a personal bubble is always an option: noise-canceling headphones start at around $50.

    Technology makes listening to holiday music easier than ever. There are endless sources to help you find your favorite Christmas tunes and many other songs. People have explored how to listen to holiday music with high-tech devices (设备).

    Apple Music

    This is the first year you can use Apple Music to listen to holiday songs. Apple  Music has more than 30 million songs and is available (可获得的) in over 100 countries.

    Tell voice assistant Siri to "play holiday music" to open the music program on your iPhone, iPad or Apple TV. Have an Android phone? Apple Music app is available in the Google Play store, but not with a voice assistant. For the first three months, you can use it for free. After that, users have to pay a subscription (订购) fee.

    Google Play Music

    Google Play Music is also in the holiday spirit. Go to the Google Play Music Holiday page and search for "holiday music."

    Google Play Music is available for free if you don't mind the advertisements. If you do, buy a paid subscription to avoid them. Google Play Music offers more than 30 million songs from 58 countries.

    Tune In Radio

    Listen to radio stations with Tune In Radio. This is an online service and offers stations from all seven continents in the world, including Antarctica. Tune In Radio is available on your computer and is free to online users. In the United States, Britain and Canada, a paid subscription gives you more stations without advertisements.

    If you want to know more, please click here.

So far this winter, a theater in the Alps has staged more than 60 unique concerts. Winter temperatures in the remote mountain village can drop high below zero. Performers wear down jackets and play ice instruments. In fact, almost everything from drums and guitars to horns and harps at the music festival is carved from ice even the stage the musicians play on. The audience sits on ice chairs and benches and claps their hands to listen, both to praise the performers and to keep themselves warm when the air flows through.

The musical instruments used were almost entirely made by an American ice artist, Tim Linhart. Since he created his first musical instrument out of ice more than a decade ago, he has already carved various ice instruments, including violins, violas, timber drum sets, xylophone, double bass, mandolin and cello. He also created his own large wind instrument, which uses the vibration of an ice tube to produce sound when the air flows through.

Linhart makes the different parts of the ice instrument and then uses a liquid mixed with snow to glue them together, with a metal support placed where the strings need to be. A violin can usually be made in two or three weeks, while larger instruments can take more time and efforts, sometimes taking months to make.

An ice instrument has a clearer sound than a wooden instrument. However, ice instruments are more easily broken or damaged than ordinary instruments. The temperature in the ice theater changes depending on the number of people in the audience. This also changes the temperature of the ice instruments, which in turn affects the 1 sound they produce. Musicians need to tune their instruments frequently during performances.

Although playing an ice instrument is not easy, Linhart believes that ice and snow are good materials for making instruments. The only downside is melting when the temperature is above freezing.

There is increasing evidence suggesting that ultra-processed food addiction is indeed a significant issue. These foods, which are carefully manufactured in industrial factories rather than in the familiar setting of grandma's kitchen, are filled with altered ingredients that are artfully combined to enhance fat, sugar, and salt levels. Moreover, they contain a lots of flavor and sensory enhancers, which render them irresistibly appealing. Examples of ultra-processed foods range from packaged snacks to fast food and mass-produced desserts. In fact, they account for nearly 60 percent of the calories consumed in the United States.

Studies have revealed that up to 20 percent of adults and 15 percent of kids and adolescents might exhibit signs of addiction to these foods, a phenomenon that has been recognized for decades as rat studies in the 1980s demonstrated that the brain's reward system is powerfully activated when rats consume certain foods, a reaction similar to that when they self-administer cocaine.

In recent years, as the obesity rate in America has soared to 42 percent, especially among Black and Hispanic populations, scientists have been devoting increased attention to the impact of ultra-processed food addiction. These foods not only activate the brain's reward system but also may involve the gut-microbiology. Symptoms of craving and withdrawal are clearly evident with ultra-processed foods. People will go to great lengths to obtain these foods, and when they are refused, they may experience a series of discomforts such as headaches, fatigue, and irritability(易怒的). A study in 2022 found that ultra-processed foods meet the same addiction criteria as tobacco products.

High consumption of ultra-processed foods is linked to numerous health problems, including heart disease, type 2 diabetes, obesity, depression, anxiety, and an increased risk of death. Thin people can also be addicted, perhaps burning off the extra calories through exercise or having a genetic predisposition(易患病体质) not to gain weight easily. Food companies argue against denying these foods, but experts advocate for clear nutritional labels and restrictions on marketing to children. Treating food addictions remains an open question, but there is hope that people will become more aware of the dangers, just as they did with smoking.