The weather is getting hotter and you'll be getting thirstier playing basketball or riding home from school. A cold drink may be just the thing. But be careful what you pour down your throat. Something that looks cool may not be good for your health.

    There are plenty of so-called energy drinks on the market. Most of them have an attractive colour and cool name. Their nutrition list also contains various things from vitamins to ginseng. Sounds great!

    But after a careful check you may find that most energy drinks contain high levels of caffeine. These drinks are typically aimed at young people, students, busy people and sports players.

    Makers sometimes say their drinks make you better at sports and can keep you awake. But be careful not to drink too much.

    Caffeine raises your heartbeat. Because of this, the International Olympic Committee has limited their use. The amount of caffeine in most energy drinks is at least as high as in a strong cup of coffee or strong tea.

    Research by Australian scientists has found that many teenagers are affected by caffeine. The results of their survey show that 27 percent of boys aged 8-12 take in more caffeine than their parents.

    There are potential health risks linked to energy drinks. Just one can of energy drink can make you nervous, have difficulty sleeping and can even cause heart attacks.

    Teenagers should be discouraged from consuming drinks with a lot of caffeine in them, an expert from the Australia Nutrition Foundation said.

    When Kate's paintings were on show in London，a poet described her paintings as “a ribbon (丝带）around a bomb”．Such comments seem to suggest Kate had a big influence on the art world of her time．Sadly，she is actually a much bigger name today than she was during her time．

    Born in 1907 in a village near Mexico City，Kate suffered from polio（小儿麻痹症）at the age of seven．Her spine (脊柱)became bent as she grew older．Then，in 1925，her back was broken in several places in a school-bus accident．Throughout the rest of her life，the artist had many operations，but nothing was able to cure the terrible pain in her back．However，the accident had an unexpected side effect．While lying in her bed recovering，Kate taught herself to paint．

    In 1929，she got married to Diego Rivera，another famous Mexican artist．Rivera's strong influences on Kate's style can be seen in her early works，but her later works from the 1940s，known today as her best works，show less influence from her husband．

    Unfortunately，her works did not attract much attention in the 1930s and1940s，even in her home country．Her first one-woman show in Mexico was not held until 1953．For more than a decade after her death in 1954，Kate's works remained largely unnoticed by the world，but in the 1970s her works began to gain international fame at last．

    Eighteen years ago, Terry Grahl, was pregnant with her fourth child. “Money was very tight,” Terry recalls. So when her mom called to ask if she'd like to go shopping at the local fabric(布料) store for the coming Christmas, she couldn't say no because she knew she badly needed some fabrics to make new clothes for her children. “I remember walking around, gazing at all this beautiful fabric, wondering whether there is anything cheap that I could afford. And I could still get some money left to buy Christmas gifts for my family.

    Well, Terry's mom must have known what Terry was thinking. Smiling kindly, she whispered to Terry, “You pick any fabrics you like. It's your Christmas gift from me.” Terry's eyes were filed with tears as the cart began to overflow with many fabrics, but not because Terry was planning on making herself a pretty dress or a pair of curtains for the kitchen. Rather, Terry's mom's kindness had inspired some holiday gift ideas in Terry, and it didn't take long for Terry to figure out what she was going to do with all that fabric.

    “I was going to make my first quilt,” she explains. “Every night I would work on this queen-size quilt. With every stitch(一针), I thought about all that my mom had done for me over the course of my childhood, during which we were always battling homelessness, but Mom somehow managed to fill our lives with love and make everything okay.”

    On Christmas Day, five days after her baby girl was born, Terry handed her mom a gift box. Inside was the quilt she had sewn, from the fabric her mother had given her as a gift.

    Nola (August 21, 1974 -November 22, 2015) was a northern white rhino(犀牛) who lived at the San Diego Zoo Safari Park near Escondido, California. At her death, she was one of only four remaining northern white rhinos in the world. The other three lived in Kenya. World Rhino Day, held on September 2, is to raise awareness(意识) of the less than 30,000 other rhinos left on Earth.

    “Rhinos need our help today, not tomorrow,” Nola's lead keeper Jane Kennedy said. “Last year we lost over 1,200 rhinos just in South Africa. If we continue to lose more than 1,000 rhinos a year, in 10 to 20 years all the rhinos on the planet will be gone.”

    “Unfortunately, most animals are in danger of dying out because of humans,” Kennedy says.“ Humans have either poached animals, or because there are over seven billion of us, we've taken up too much of the world's resources ”. Poachers illegally hunt rhinos for their horns. They sell the horns for thousands of dollars per pound, to be used for art, jewelry, and decorations. Experts believe that one rhino is poached every eight hours.

    In 1975, the San Diego Zoo Institute for Conservation Research started the Frozen Zoo, a program through which researchers have collected cell (细胞) samples from more than 8,000 different types of animals, including the northern white rhino. Scientists hope that by studying the rhino cells, they will get greater understanding of it, and will find ways to increase its numbers.

    Jane Kennedy describes World Rhino Day as “a celebration of rhinos along with an awareness campaign for everybody across the world to know that rhinos need our help.” At the San Diego Zoo, children and adults are welcome to visit and speak with zookeepers to learn about rhinos. But you don't have to live in San Diego to celebrate World Rhino Day. It is observed around the world, with zoos and wildlife parks holding special events and programs to teach people about rhinos, and enable them to see the animals up close. For more information, go to www.worldrhinoday.org.

    It's a safe bet that a robot made your car and made your computer. Pretty soon, they could be making your bed and breakfast too.

     Increasingly, engineers are saying that robots are going to move out of research departments and into your home. Companies including General Electric are working on designs for small robots. Products like the Roomba, a robot that can clean floors, are flying off the shelves.

     What's behind this new robot revolution? It's partly a matter of technology. Devices that can recognize and respond to a human voice have been developed. There are now a few different ways for robots to move around. They can walk, crawl or ride on wheels. Robots are being made smaller and smaller. They are also becoming more and more able.

     A bigger part of the story is on the demand side. From the day the television remote control was invented, people around the world have searched for new ways to be lazy. Take into consideration that more and more people can afford robots, and the time seems ripe to introduce robots to the ordinary family.

     To be sure, robots that walk on two legs and talk like people are still a long way off. However, robots that do basic housework such as cleaning or gardening are sure to come out soon. One thing is certain—when these robots do come into our homes, it will change things forever.

    A few weeks ago, I sat with a California farmer named Dave Ribeiro. I asked him what he wished to know about farmers. He smiled and said, "That we walk among you. We look like you and talk like you. We have advanced degrees and hobbies, just like you."

    Take Dave for example: He's a young man with a music degree. And if you walked past him on the street, you'd never think, "There goes a farmer."

    Is someone like Dave who you picture when you think of a farmer? Probably not. I think that most people would picture a man in his overalls(工作服). I can tell you, that does not represent Dave or any of the many other farmers I have gotten to know.

    Not only do we have to throw out our previous impression of farmers, but farming as a whole doesn't look much like it used to either. We recently sent a team out to see what modern farming looks like, and they found farmers to be completely different from our usual ideas about them and also came across them in some unexpected places.

    In a parking lot in a neighborhood of Brooklyn, they met a new crop of young farmers who were trying to bring fresh greens closer to eaters in the city by growing them in high-tech indoor vertical(垂直的) farms. In a Florida field under the fight path of an airport, they discovered farmers with university degrees growing plants that might someday fuel our cars. And in a modern farm in California, they observed how farmers were using technology to take the best possible care of their animals.

    These farmers all spend their days in very different ways—none of them looks like the previous farmer we have in our mind—but they're all working on new ways to feed our planet. Not only do we need to change our idea of what farming looks like, but we also need to change our view of where solutions can come from. Feeding all of us is going to take all of us working together.