Sweet or salty? What kind of tastes do you like? If like me, you have a sweet tooth and you probably can't resist eating cakes, biscuits or chocolate and will sweeten your tea or coffee with spoonfuls of sugar-delicious! But the taste makes it very easy to ignore the warnings that too much of the white stuff（东西）is bad for our health.

    Consuming sugar is an addiction-the more we eat, the more we want. Today's processed food, like ready meals, is related to the stuff and many fizzy（起泡的）drinks contain seven teaspoons of sugar in just one can. In the UK, statistics show that sugar consumption is at its highest level in history and the government is trying to get the food industry to cut the amount of sugar in popular products like chocolate bars by 20% by 2020.

    Of course, sugary food tastes nice, it can help lift our mood, and a part in it can refresh us. But there are dangers too :a high-sugar diet is linked to putting on weight, and being overweight can increase the risk of getting type 2 diabetes（糖尿病）. With these warning signs, I have considered changing my diet by replacing sugary snacks with fruit and salty biscuits-but that's boring!

I'm not alone. BBC journalist Radhika Shanghani, has gone one step further. Encouraged by some well-knowns and nutritionists promoting a 'zero tolerance' approach to sugar, she gave it up altogether, thinking it would make her healthier. Initially she says, “My first fortnight involves mood swings. I have disturbing headaches and feel permanently hung-over.” These symptoms disappeared but she still found food shopping hard as she was stressing about buying the right things.

    Her experiment wasn't a success. She eventually sought advice from Susan Jebb, professor of diet and population health at Oxford University who said: “Lots of people enjoy sugar and gain pleasure from it, so one has to find a balance between enjoyment and eating the right amount.”

    Does the future of filmmaking lie in virtual reality (VR) films?

   An ambitious team led by Yale senior Celine Tien might hold the answer to that question.

    Tien produced,directed and acted in Pippa's Pan,which she says is “one of the world's first live-action VR films.”The film,which was completed in April,mixes live action with VR sections.Some of the characters were created via animation（动画）and other techniques that distinguish the film from 360° VR videos like the ones frequently seen on YouTube.

    “360° VR videos are stagnant,which means you don't move with them and see a 360° view of whatever they're filming.”Tien explained.“What we're doing is immersive（沉浸式的）VR.When you put on the goggles (a kind of special glasses) you can physic.ally walk around in the space,pick up objects and engage with the environment.It's a huge difference.”

    The immersive VR film experience is different for everyone who interacts with the medium,but that doesn't mean the film's ending will change for each viewer.

    The film stars two Chinese-speaking actors."It's a love story about a woman suffering from Alzheimer's disease who is trying to bring back memories of her husband,"Tien said.

    The film has already been recognized by the VR industry.After handing in a short demo to the AT&T Developer Summit Conference,Tien and her team were invited to Las Vegas in January,where they came in third place.

    If you're dying to see the film already,your choices area bit limited: Pippa's Pan can't be seen in movie theaters unless they happen to have VR goggles available.According to Tien,many theaters in China will soon have the ability,which makes sense considering China is the film's target market.

    Pippa's Pan will be released in three languages: Chinese,English and Korean.“It can get spread in different ways: at film festivals with VR set ups and through HTC or Oculus headset stores,”Tien says.“If you have VR goggles you can download it and experience it yourself.We will also cooperate with movie theaters that have VR set ups.”

    Over the past few years, smart home tech has become more and more accessible and it's increasingly easy to find that you've bought a product that includes smart home features. So what does a modern smart home look like, and how can you start building one? You could get to start making your home smarter by the following gadgets.

    Ecobee 4

    *Measuring both occupancy and temperature, its sensors signal your Ecobee to automatically switch to the right mode.

    It only takes about 30 minutes, thanks to an easy-to-follow installation guide and an in-app step-by-step walkthrough.

    Easily adjust temperature using your voice with built-in Alexa or from wherever you are using your mobile devices.

    Amazon Smart Plug

    Amazon Smart Plug works with Alexa to add voice control.

    Schedule lights, fans, and appliances to turn on and off automatically, or control them remotely when you're away.

    It's simple to set up and use. Plug in, open Alexa app, and start using your voice.

    The Philips Hue White Smart Bulb

    It works with Amazon Alexa to support dimming through voice control.

    Schedule your own custom lighting scenes. Set the smart bulbs to turn on and off at a pre-set time.

    To install, simply screw(拧) the smart bulbs into your desired light location.

    Control smart-bulb-equipped lamps and overhead lights via the Philips Hue App.

    August Smart Lock Pro

    It works with Alexa for voice control(Alexa device sold separately).

    Control keyless access. It locks automatically behind you, and unlocks as you approach.

    Install in about 10 minutes with just a screwdriver(螺丝刀).

    It is important to know another language and how to communicate without words when you are in another country. Before saying anything, people communicate with each other by using gestures(手势). However, many gestures have different meanings, or no meaning at all, in different parts of the world.

    In the United States, nodding your head up and down means "yes", while in some parts of Greece and Turkey, it means "no". In the southeast of Asia, it is a polite way of saying "I heard you".

    Today in the USA, when someone puts his thumb up, it means "Everything is all right." However, in Greece it is bad. Also putting your clasped(紧握的)hands up above your head means "I am the winner." It is the sign which players often make. In Russia it is the sign of friendship.

    In the USA, holding your hand up with the thumb and index finger(食指), and the other three straight means "Everything is OK." In France, it means "You are worth nothing."

    It is also important to make eye communication. If you look down when talking to an American, he or she may feel that you are shy, or you are trying to hide something.

Besides these, you should also know there are some topics that cannot be talked about, such as age, weight and marriage. You can talk about the weather, work, sports, food, where one lives and news of the day.

    It's common knowledge that the woman in Leonardo da Vinci's most famous painting seems to look back at observers, following them with her eyes no matter where they stand in the room. But this common knowledge turns out wrong.

    A new study finds that the woman in the painting is actually looking out at an angle that's 15.4 degrees off to the observer's right­well outside of the range that people normally believe when they think someone is looking right at them. In other words, said the study author, Horstmann, "She's not looking at you." This is somewhat ironic, because the entire phenomenon of a person's gaze (凝视) in a photograph or painting seeming to follow the viewer is called the "Mona Lisa effect" . That effect is absolutely real, Horstmann said. If a person is illustrated or photographed looking straight ahead, even people viewing the portrait from an angle will feel they are being looked at. As long as the angle of the person's gaze is no more than about 5 degrees off to either side, the Mona Lisa effect occurs.

    This is important for human interaction with on-screen characters. If you want someone off to the right side of a room to feel that a person on-screen is looking at him or her, you don't cut the gaze of the character to that side­surprisingly, doing so would make an observer feel like the character isn't looking at anyone in the room at all. Instead, you keep the gaze straight ahead.

    Horstmann and his co-author were studying this effect for its application in the creation of artificial-intelligence avatars(虚拟头像) when Horstmann took a long look at the "Mona Lisa" and realized she wasn't looking at him.

    To make sure it wasn't just him, the researchers asked 24 people to view images of the "Mona Lisa" on a computer screen. They set a ruler between the viewer and the screen and asked the participants to note which number on the ruler intersected Mona Lisa's gaze. To calculate the angle of Mona Lisa's gaze as she looked at the viewer, they moved the ruler farther from or closer to the screen during the study. Consistently, the researchers found, participants judged that the woman in the "Mona Lisa" portrait was not looking straight at them, but slightly off to their right.

    So why do people repeat the belief that her eyes seem to follow the viewer? Horstmann isn't sure. It's possible, he said, that people have the desire to be looked at, so they think the woman is looking straight at them. Or maybe the people who first coined the term "Mona Lisa effect" just thought it was a cool name.

    There are many places to go on safari (观赏野生动物) in Africa, but riding a horse through the flooded waters of Botswana's Okavango Delta must rank as one of the world's most exciting wildlife journeys.

    Several safari camps operate as the base for this adventure, providing unique rides twice a day to explore deep into the delta. The camps have excellent horses, professional guides and lots of support workers. They have a reputation for providing a great riding experience.

    The morning ride, when the guides take you to beautiful, shallow lakes full of water lilies, tends to be more active. It is unlike any other riding experience. With rainbows forming in the splashing water around you and the sound of huge drops of water bouncing off your body and face, it is truly exciting. You are very likely to come across large wild animals, too. On horseback it is possible to get quite close to elephants, giraffes and many other animals. The sense of excitement and tension levels rise suddenly though, as does your heart rate, as you move closer to them.

    In the evening, rides are usually at a more relaxed and unhurried pace, with golden light streaming across the grassy delta and the animals coming out to eat and drink. Sedate though they are, rides at this time of day are still very impressive. As the sun's rays pass through the dust kicked up by the horses, the romance of Africa comes to life.

    Back at the camp you can kick off your boots and enjoy excellent food and wine. Looking back on your day, you will find it hard to deny that a horseback safari is as close as you will ever come to answering the call of the wild.