Sunscreens (防晒霜) can offer protection from two types of ultraviolet (UV) rays (紫外线): UVB, which according to the Skin Cancer Foundation, are the chief cause of sunburn and play a key role in the development of skin cancer, and UVA, which get through the skin more deeply and are largely responsible for skin aging and wrinkling, as well as skin cancer risk. The SPF (防晒指数) measurement on sunscreens refers to the UVB protection level — and the number may not mean what you think it does. SPF 15 doesn't protect you from 15% of UVB rays, just as SPF 100 doesn't protect you from 100% of the rays. In fact, as you get into the higher numbered SPF sunscreens (think: 50 and above), the difference in UVB protection is actually pretty small.

    Theoretically, though the increase in UVB protection with a super-high SPF sunscreen may be not worth considering, it may help, and certainly can't hurt, to use it — that is, as long as you do so correctly. “The only downside is whether you're giving yourself a sense of false security,” Dr. Gohara says.

    Indeed, as Dr. Wang also pointed out, when people choose increased SPFs, they may actually feel so protected by the product that they finally ignore proper sun protection. “When people use really high SPF products, they tend not to reuse, they tend to stay out in the sun much longer, and they don't use other protective measures such as clothing and hats,” he says. Regardless of any increase in protection that a high SPF may or may not offer, one thing is certain: It doesn't give your body a free pass from sunburns, aging, or cancers, and it doesn't protect you from those things for any greater length of time than the lower SPF options. Both Dr. Wang and Dr. Gohara emphasized that, no matter what the SPF is, it's important to reapply your sunscreen every two hours.

    Time for an adventure?

    Are you a bit bored with your nine-to-five routine? Have a look at our exciting range of holidays and decide what type of adventure you'd like.

    Activity holidays

    Our activity holidays are for everyone, people who love danger or who just like sports. We have a huge variety of water, snow or desert holidays. We'll take you SCBA diving in the Red Sea or kayaking and white water rafting in Canada. If you prefer snow, you can try skiing or snowboarding in the. Alps or even igloo building. For those who like warmer weather, we also have sandboarding (the desert version of skateboarding) or camel safaris.

Polar expeditions

    Take an expedition to Antarctica or the northern Arctic; explore a land of white natural beauty and wonderful wildlife. Our experts will explain everything about the two poles as you watch the penguins in Antarctica or whales and polar bears in the Arctic, There's no greater adventure than travelling to the ends of the earth. A once-in-a-lifetime experience.

Cultural journeys

    Our cultural journeys will help you discover ancient civilizations: India, Thailand, Egypt and many more. Visit temples, palaces and ancient ruins—just remember to bring your camera! Get to know local ways of life by exploring markets, trying exotic foods and meeting local people.

Wildlife holidays

    We organize small - group tours to get closer to nature in Africa, Asia or South America. Go on safari in Africa and watch lions and giraffes. Meet the famous turtles off the Galapagos Islands, Look for tigers in India, or take an elephant safari in Sri Lanka. We use local guides and stay in a range of accommodation, from tents to tree houses.

    You can either travel or read, but either your body or soul must be on the way. The popular saying has inspired many people to read or go sightseeing. Traveling, just like reading, is a refreshing journey from the busy world. Books, brain food, can keep you company on your travel.

    ⒈On the Road, 1957, by Jack Kerouac

    The book is a globally popular spiritual guide book about youth. The main character in the book drives across the US continent with several young people and finally reaches Mexico. After the exhausting and exciting trip, the characters in the book begin to realize the meaning of life. The book can be a good partner with you to explore the United States.

    ⒉Life is Elsewhere, 1975, by Milan Kundera

    Jean-Jacques Rousseau once said, “Man is born free, and everywhere he is in chains.” The book tells a young artist's romantic but miserable life, about how he reads, dreams and has a relationship. Experience the artist's passionate life in the book during a trip to Central Europe. The book invites you to deeply reflect on your current life.

    ⒊The Stories of the Sahara, 1967, by Sanmao

    The book narrates the author's simple but adventurous life in the Sahara Desert, which seems a desolate and dull place. The fancy natural scenery and life there, along with the author's romantic and intensive emotions will inspire you to explore the mysterious land. Reading the book is like participating in a dialogue with the author, who is sincere and humorous.

    ⒋Lotus, 2006, by Annbaby

    This novel set in Tibet, tells three people's stories, each with their unique characteristics. It reveals modern people's emotions and inner life, their confusion about love, and exploration of Buddhism. The book is a good partner to bring you to the scared land Tibet.

    Mary Lyon was a leader in women's education in the nineteenth century. It was a time when women's education was not considered important in the United States. States did require each town to provide a school for children, but there were not enough teachers. Most young women were not able to continue their education. If they did, they often were not taught much except the French language, how to sew clothing, and music.

    Mary Lyon felt that women's education was extremely important. She believed women were teachers both in the home and in the classroom. Mary opened a school for young women in the village of Buckland. She suggested new ways of teaching, including holding discussion groups for students.

    Then, Mary began to raise money for her dream school for the higher education of women. This school would own its own property (财产), guided by an independent group of direction. Its finances would be the responsibility of the directors. It would not depend on any one person to continue. And, the students would share in cleaning and cooking to keep costs down. In 1837, Mary Lyon opened Mount Holyoke Seminary for Women. In 1893, 34 years after her death, under a state law, Mount Holyoke Female Seminary became the first college to offer women the same kind of education as men.

    Mary's efforts led to the spread of higher education for women in the United States. Her influence lasted as the many students from her schools went out to teach others.

    A shark moving around the coastline is normally a worrying sight，but this waterborne drone (无人机) threatens floating rubbish instead of people.

    Developed by Dutch company RanMarine, the WasteShark takes nature as its inspiration with its whale shark-like mouth. Responsible for collecting waste, the drone will begin operations in Dubai Marina in November after a year of trials with local partner Ecocoast.

    According to RanMarine, the WasteShark is available in both autonomous and remote-controlled models. Measuring just over five feet by three-and-a-half feet (1.5 meters by 1.1 meter), it can carry up to 352 pounds of rubbish (159.6 kg) and has an operational battery life of 16 hours.

    By 2016 there were approximately 150 million tons of plastic in the world's oceans. One paper from December 2014 estimated that over a quarter of a million tons of ocean plastic pollution was afloat.

    "WasteShark also has the abilities to gather air and water quality data, remove chemicals out of the water such as oil, and heavy metals, and scan the seabed to read its depth and outlines," said Oliver Cunningham, one of the co-founders of RanMarine. "Fitted with a collision-avoidance system, the drone uses laser imaging detection and ranging technology to detect an object in its path and stop or back up if the object approaches."

    "Our drones are designed to move through a water system, whether it's around the perimeter (周边) or through the city itself. The drones are that last line of defense between the city and the open ocean," added Cunningham. "WasteSharks are operating in Dubai, South Africa and the Netherlands and cost $ 17, 000 for the remote-controlled model and just under $ 23, 000 for the autonomous model."

    Dubai-based operator Ecocoast has two WasteShark drones. Co-founder Dana Liparts says they will clean waterfronts for clients including hotels and environmental authorities and that Ecocoast' intention is to have the collected rubbish recycled or upcycled. However, Liparts argues that cleaning waterways doesn't have a one-size-fits-all solution and requires a combination of new technology, preventative measures and changing people's attitudes towards littering.

    Plastics remain one of the most - used materials for making many things. Things made of plastics can be very strong and last a long time. Plastics are also much lighter than metal and can easily be formed into different shapes. Plastics can take hundreds of years to break down on their own. And very few kinds are highly recyclable.

    A team of researchers working at the US Department of Energy says it has created a kind of plastic that could lead to products that are 100 percent recyclable. It recently reported the discovery in a study in the journal Nature Chemistry.

    The researchers say the new material is a plastic polymer (聚合体)called polydiketoenamine, or PDK. The team reports the material can be broken down in parts at the molecular (分子的)level. It can then be built up again to form plastics of different shapes, textures and colors. The researchers say this process can be repeated over and over again—without the plastic material losing any performance or quality.

    "Most plastics were never made to be recycled," lead researcher Peter Christensen said in a statement. " But we have discovered a new way to assemble plastics that takes recycling into consideration from a molecular perspective. "

    Many plastics have different chemicals added to them to make them more useful and powerful. The problem is that these chemicals attach to the monomers (单体), which remain in plastics even after the material gets processed at a recycling plant. The research team reported that, with the newly discovered PDK material, the monomers could be recovered and separated from any chemical additives.

    Next, the researchers plan to develop PDK plastics "with a wide range of thermal and mechanical properties. These plastics could be used for many kinds of cloth, as well as things such as 3D printed materials and foams. In addition, the team is trying to include plant - based materials in the process.