To help the environment, many Americans have made the change from paper and plastic bags to reusable shopping bags.But a report by a Florida newspaper says that reusable shopping bags sold by some supermarkets have high levels of lead(铅), which can be dangerous to humans, especially young children.Now, there's a call for a rethink about the use of reusable shopping bags.

     “When our families go to the store looking for safe and healthy foods, the last thing they should be worrying about is a bag，”Charles Schumer, a government official said.“Quick and complete research will allow everyone to make right decisions.”

    The newspaper bought more than a dozen bags sold at Publix supermarkets from Florida supermarkets to test them for lead.The results showed that certain bags had lead levels that worried health officials.Some bags had enough lead in them to be considered dangerous waste if people were to throw the bags out with other rubbish.Lead in the bags is not likely to move onto food.But over time, paint (油漆) on the bags can break off and the bags can wear out.When this happens, lead can be freed.

    The affected (受影响的) bags were found in Florida.But Publix has more than 1，000 stores across America.Publix says that its bags don't break any laws about lead levels, but that they have asked the makers of the bags to reduce(降低) the lead levels in them.

    The bags with the highest levels of lead had beautiful designs and many pictures.Plain reusable bags without them are found to have little lead.People worried about lead levels in reusable bags can turn to cloth.Paper bags are also a good choice, since paper can be reused.

    Look to many of history's cultural symbols, and there you'll find an ancestor of Frosty, the snowman in the movie Frozen. It appeared on some of the first postcards, starred in some of the earliest silent movies, and was the subject of a couple of the earliest photos, dating all the way back to the 1800s. I discovered even more about one of humanity's earliest forms of life art during several years of research around the world.

    For example, snowmen were a phenomenon in the Middle Ages, built with great skill and thought. At a time of limited means of expression, snow was like free art supplies dropped from the sky. It was a popular activity for couples to leisurely walk through town to view the temporary works of chilly art. Some were created by famous artists, including a 19-year-old Michelangelo, who in 1494 was appointed by the ruler of Florence, Italy, to build a snowman in his mansion's courtyard.

    The Miracle of 1511 took place during six freezing works called the Winter of Death. The city of Brussels was covered in snowmen—an impressive scene that told stories on every street corner. Some were political in nature, criticizing the church and government. Some were a reflection of people's imagination. For the people of Brussels, this was a defining moment of defining freedom. At least until spring arrived, by which time they were dealing with damaging floods.

    If you fear the heyday of the snowman has passed, don't worry: I've learned that some explosive snowman history is still being made today. Every year since 1818, the people of Zurich, Switzerland, celebrate the beginning of spring by blowing up a snowman. On the third Monday of April, the holiday Sechselauten is kicked off when a cotton snowman called the Boogg is stuffed with explosive and paraded through town by bakers and other tradesmen who throw bread to the crowds. The parade ends with the Boogg being placed on a 40-foot pile of firewood. After the bells of the Church of St. Peter have rung six times, representing the passing of winter, the pile is lit. When the snowman explodes, winter is considered officially over—the quicker it is burnt down, the longer summer is said to be.

    I must have looked deep in thought, or as deep in thought as an 11-year-old man can, when my grandmother glanced up from her weeding to ask, "You have something on your mind, don't you?"

    "Yes, I was thinking that someday I want to be an Olympic speedskating champion like my hero, Eric Heiden, I want to be a doctor like my parents and I want to help children in Africa."

    I immediately knew I had confided in the right person when a knowing smile broke across her face. "Johann, of course! You can do anything you want to do!" she said simply. And with my grandmother's support, I set out to pursue my passions.

    14 years later, I was well ready to take hold of my first dream: becoming an Olympic champion. The Olympics in 1994 were in my home country, Norway. As I entered the Olympic stadium, I wasn't the best athlete, and many had doubts about my ability to perform well. But I had something special working for me. I had a woman in the first row who believed in me following my passions just as much as I did. For the first time ever, my grandmother was going to see me skate.

    It happened. Breaking a world record, I won the gold.

    As I stood on the podium(领奖台) that I had dreamed about my entire life, a curious question popped into my head. Why me? Why did I win, given all the other incredible competitors out there? The reason had to be more than a grandmother who shared a belief in her grandson's dream. The question led me to only one answer: because I wanted to make a difference in the world, and with all the media attention on my success, I could.

    I immediately knew what that difference had to be: hope in the lives of the children in Africa. Six months earlier, I'd been invited to Eritrea as an ambassador for Olympic Aid.

    Chocolate is good for your heart, skin and brain. Usually, people think that chocolate is bad for their health. They describe chocolate as “something to die for” or say “death by chocolate”. Now they should bite their tongues! Evidence is showing that some kinds of chocolate are actually good for you in the following ways:

    A happier heart

    Scientists at Harvard University recently examined 136 studies on cocoa—the main ingredient in chocolate and found that it does seem to strengthen the heart．Studies have shown heart benefits from increased blood flow. These benefits are the result of coca's chemicals, which seem to prevent both cell damage and inflammation (炎症)．

    Better blood pressure

    If yours is high, chocolate may help. Jeffrey Blumberg from Tufts University recently found that people with high blood pressure who ate 3.5 ounces of dark chocolate per day for two weeks saw their blood pressure drop quickly.

    Muscle magic

    Chocolate milk may help you recover after a hard workout (锻炼). In a small study at Indiana University, people who drank chocolate milk between workouts did better on a tiredness test than those who had some sports drinks.

    Better for your skin

    German researchers gave 24 women a half-cup of special cocoa every day. After three months, the women's skin was moister (滑润的) and smoother. The research shows that chocolate helps protect and increase blood flow to the skin, improving its appearance．

Brain gains

    It sounds almost too good to be true, but research suggests that chocolate may improve your memory, attention span, reaction time, and problem-solving by increasing blood flow to the brain．

    These days, more and more Chinese people enjoy sending and receiving messages on the phone. It can help them to get the latest news and communicate with friends. But I think I should read more books besides the textbooks, the more, the better. It can open my eyes and improve my language skills. Of course, it also can help me to get good grades. Do you know how to read more and learn more? Here are some tips for you.

    Clear your purpose for reading

    Before you start reading, ask yourself why you are reading this book. Most people read for two main reasons, pleasure or knowledge. Clearing about your reading purpose can not only help you choose the books you really need to read, but also remind you why reading the book is important to you, so you will keep reading and complete the book faster.

    Read only what you are interested in

    No matter what you are reading, it is important to enjoy what you read. Your friends may tell you the books they love, but those books might not necessarily be the ones you enjoy.

    Give up books that you don't enjoy

    You may have chosen books that you are interested in, and they are right to your purpose. But while you are reading them, there may still be some books that you don't enjoy reading. Whenever you realize that you aren't enjoying the book you are reading, give it up. Remember reading shouldn't be a chore (苦差事).

    Set a reading goal

    It is interesting that I read the books borrowed from libraries faster than those I bought. The reason is the books I bought don't have a due date! I don't need to return those books. Having a reading goal helps you work out how much reading you need to do in a week or even a day. Before you read each book, ask yourself what time you need to complete this book by.

    Taking your pulse during physical activity allows you to measure how hard you are exercising. You should exercise to stay within your target heart range.

    Increasing your heart rate is a key part of exercise but it is important that your heart rate is not too high or too low. If you are a beginner, you should also be able to breathe comfortably while exercising. This will ensure that you are exercising at a level that is safe and effective for your body.

    The chart below illustrates target heart rate ranges for exercise based on the maximal heart rate for selected ages. Here are the steps for using the chart: