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.”

    Sports shoes that work out whether their owner has done enough exercise to warrant(保证；授权)time in front of the television have been invented in the UK.

    The shoes — named Square Eyes — contain an electronic pressure sensor and a tiny computer chip to record how many steps the wearer has taken in a day. A wireless transmitter(传话器) passes the information to a receiver connected to a television, and this decides how much evening viewing time the wearer deserves, based on the day's efforts.

    The design was inspired by a desire to fight against the rapidly ballooning waistlines among British teenagers, says Gillian Swan, who developed Square Eyes as a final year design project at Brunel University in London, UK. "We looked at current issues and childhood overweight really stood out," she says. "And I wanted to deal with that with my design."

    Once a child has used up their daily allowance gained through exercise, the television automatically switches off. And further time in front of the TV can only be earned through more steps.

    Swan calculated how exercise should translate to television time using the recommended daily amounts of both. Health experts suggest that a child take 12,000 steps each day and watch no more than two hours of television. So, every 100 steps recorded by the Square Eyes shoes equals exactly one minute of TV time.

    Existing pedometers(计步器) normally clip(夹在) onto a belt or slip into a pocket and keep count of steps by measuring sudden movement. Swan says these can be easily tricked into recording steps through shaking. But her shoe has been built to be harder for lazy teenagers to cheat. "It is possible, but it would be a lot of effort," she says. "That was one of my main design considerations."

    Many people have long dreamed of being able to fly around as simply as riding a bicycle. Yet the safety and strength of a flying bike was always a big problem. Over the past 10 years, developments in technology have moved the dream of personal flying vehicles closer to reality. Now, two groups of inventors say such vehicles may be available soon.

    The British company Malloy Aeronautics has developed a prototype (原型) of its flying bicycle. Grant Stapleton, marketing sales director of Malloy Aeronautics, says the Hoverbike is able to get in and out of small spaces very quickly." It can be moved across continents very quickly because it can be folded and packed," he adds.

    Mr. Stapleton says safety was the company's main concern. He says the designers solved the safety issue by using overlapping rotors to power the vehicle.

    The company is testing a full-size prototype of the Hoverbike, which will most likely be used first by the police and emergency rescue teams.

    In New Zealand, Martin Aircraft Company is also testing a full-size prototype of its personal flying device, called the Jetpack. It can fly for more than 30 minutes, up to 1, 000 meters high and reach a speed of 74 kilometers per hour.

    Peter Coker is the CEO of Martin Aircraft Company. He said the Jetpack "is built around safety from the start". In his words, "Reliability is the most important element of it. We have safety built into the actual structure itself, very similar to a Formula One racing car.

    The Jetpack uses a gasoline-powered engine that produces two powerful jet streams. Mr. Coker says it also has a parachute that would be used, if there should be an emergency. "It starts to work at very low altitude and actually saves both the aircraft and the pilot," he adds. Mr. Coker says the Jetpack will be ready for sale soon.

    Do you ever pull your phone out of your pocket, thinking it is vibrating(振动), only to find that it isn't? This phenomenon, which scientists call "phantom(幻觉的)phone vibration", is very common. Around 80% of people surveyed say they have imagined their phones vibrating when they were actually still.

    So, what leads to this universal behavior? According to the BBC, the explanation lies in your brainˈs ability to discover signals from the outside world. When your phone is in your pocket, there are two possible states: it is either vibrating or not. Meanwhile, you also have two possible states of mind: the judgment that the phone is vibrating, or that it isn't. Ideally, you match the four states correctly.

However, sometimes your brain decides that the results of missing a call are more serious than a "false alarm". Therefore, you become more sensitive(敏感的) to vibrations so that you don't miss anything. This is just like the fire alarm in your home—it can be annoying when it goes off in response to just a tiny bit of smoke. But that's a small price to pay compared to a fire really breaking out because the alarm fails to alert you. Now, you might still ask: why can't our brains just make every judgment correctly without being too sensitive to false signals? The answer is that your brain bears a heavy burden every day. "You get a large amount of sensory(感觉的) information that's coming from your eyes, ears and skin, and you can't deal with all that information all the time, "Michael Rothberg, a researcher at Baystate Medical Center in Springfield, US, told Live Science.

    For example, the rustling(沙沙声)of clothing or the growling(咕咕声)of your stomach may both lead your brain to believe that they come from the vibration of your phone-it is like trying to hear your name being called in a noisy room.

    So, perhaps you should just check your phone whenever you think it's vibrating. It's not too much trouble to do that, is it?

Dear Max,

It must seem a little odd to get a letter from your own mother who m you see every day, but I hope you will read this and take what I have to say seriously. 

I bought you a phone for your 12th birthday because you wanted one so much, and all your friends have one. I know you love your phone, but I wonder whether you are aware of just how much you use it. 

From my perspective, it seems that you are constantly checking your phone for notifications（通知） or messages. You even do this when we're having a family meal in a restaurant or when I'm talking to you. You may not realise this, but whenever you feel even slightly bored, you check your phone. You never seem to relax. You're constantly on alert, and I don't think this is very good for you. We all need to switch it off every now and then. And if I ask you to leave your phone at home when we go out, you sulk（生气） and get twitchy, almost as if you're suffering withdrawal symptoms（戒断症状）. It's like your phone is a drug.

I have tried to talk to you about this, but whenever I ask you to put down your phone and look at me, you say "in a minute". Unfortunately, "in a minute" never comes, and we never talk. I can't actually remember the last time we had a proper face-to-face conversation. I even have to message you to let you know dinner is on the table! That's why I decided to put my concerns in a letter to you.

Please don't think I am writing this letter to punish you or to nag（唠叨） you. I know you are a good boy. I don't think you want to hurt me or be rude intentionally. However, I recently heard about something called "nomophobia"—the fear of being without a phone. It's a real illness and I'm worried whether you have it. I really think it would be a good idea if we all went to see an addiction expert together so we can all have a discussion about this serious problem. I know you won't want to, but I'm very concerned about you. Please take some time to think about what I have written. Then let's talk.

Mum, 

Back in April 1939 and armed with $5,000 provided by the Rockefeller Foundation, professor Frank Cyr at Teachers College, Columbia University took a tour of ten states to make the research about school transportation problems. What he found was that many students had no dependable way to get to school and the ones who did often travelled in unsafe buses in the over 100,000 school areas.

Seeing a need to fix this problem, Cyr organised a meeting—one that would change the future of school buses forever. School officials and transportation experts met to set much-needed standards for buses, including those for colour, height and width as well as safety rules that hadn't been set before or that were different in every state.

There were many different bus colours in the US before this meeting; several areas even planned to have red, white and blue buses as a way of encouraging students to love their country. Cyr presented his new choice to education officials, a reported "50 shades( 色度) changing from lemon yellow to deep orange red". The matter was settled quickly. Yellow, or "National School Bus Glossy Yellow", was chosen because it was quite striking, making the school bus easy to be seen. Besides, it made the bold(黑体的), black writing on the side of each bus clear. (The bold, black writing gives information about each school area, telling students which school bus they could take during early morning and late afternoon hours.) Thirty-five states made the changes quickly, and every state took them on

board by 1974.

Being recognised as the "father of the yellow school bus", Frank Cyr has surely influenced your life if you ever rode a school bus or saw that noticeable colour pulling up to your stop on a dusky morning.