How fit are your teeth? Are you lazy about brushing them? Never fear: An inventor is on the case. An electric toothbrush senses how long and how well you brush, and it lets you track your performance on your phone.

    The Kolibree toothbrush was exhibited at the International Consumer Electronics Show in Las Vegas this week. It senses how it is moved and can send the information to an Android phone or iPhone via a Bluetooth wireless connection.

    The toothbrush will be able to teach you to brush right (don't forget the insides of the teeth!) and make sure you're brushing long enough. “It's kind of like having a dentist actually watch your brushing on a day-to-day basis,” says Thomas Serval, the French inventor.

    The toothbrush will also be able to talk to other applications on your phone, so developers could, for instance, create a game controlled by your toothbrush. You could score points for beating monsters among your teeth. “We try to make it smart but also  fun,” Several says.

    Serval says he was inspired by his experience as a father. He would come home from work and ask his kids if they had brushed their teeth. They said “yes,” but Serval would find their toothbrush heads dry. He decided he needed a brush that really told him how well his children brushed.

    The company says the Kolibree will go on sale this summer, for $99 to $199, developing on features. The U.S. is the first target market.

    Serval says that one day, it'll be possible to replace the brush on the handle with a brushing unit that also has a camera. The camera can even examine holes in your teeth while you brush.

TaIL Spin

    Two dolphins race around in a big pool in the Ocean Park. The smaller dolphin Grace, shown off a few of her tricks, turning around and waving hello to the crowd. The most amazing thing about her, however, is that she's even swimming at all. She doesn't have a tail.

Grace lost her tail as a baby when she got caught up in a fish trap. When the dolphin arrived at the Ocean Park in December 2005, she was fighting for her life. “Is she going to make it?” Her trainer, Abbey Stone, feared the worst. Grace did make it — but her tail didn't. She ended up losing her flukes and the lower part of her peduncle.

Over the past six years, she has learned to swim without her tail. Dolphins swim by moving their flukes and peduncle up and down. Grace taught herself to move another way—like a fish! She pushed herself forward through the water by moving her peduncles from side to side.

    The movement put harmful pressure on Grace's backbone. So a company offered to create a man-made tail for her. The tail had to be strong enough to stay on Grace as she swam but soft enough that it wouldn't hurt her.

    The first time Grace wore the artificial tail. She soon shook it off and let it sink in the bottom of the pool. Now, she is still learning to use the tail. Some days she wears it for an hour at a time, others not at all. “The tail isn't

necessary for her to feel comfortable,” says Stone, “but it helps to keep that range of motion(动作) and build muscles(肌肉).”

    Now, the dolphin is about to get an even happier ending. This month, Grace will star in Dolphin Tale, a film that focus on her rescue and recovery. Her progress has inspired more than just a new movie. Many people travel from near and far to meet her. Seeing Grace swim with her man-made tail gives people so much courage.

    I was in a rush as always, but this time it was for an important date I just couldn't be late for! Thinking of my upcoming evening, I hurried into a store to pick up some flowers, for I did not want to be late for this date. When I paid the bill at a checkout counter, I found myself behind an elderly woman who seemed in no hurry when she paid for her groceries. She looked up at me and smiled. It was a nice smile –warm and friendly –and I returned her gift by smiling back.

    “Must be a special lady, no matter who will be getting those beautiful flowers,” she said.

    “Yes, she's special,” I said, and then to my embarrassment, the words kept coming out.

    “It's only our second date, but somehow I am just having the feeling that she's 'the one'. Jokingly, I added,“The only problem is that I can't understand why she'd want to date a guy like me.”

    “Well, I think she's very lucky to have a boyfriend who brings her such lovely flowers and who is obviously in love with her,” the woman said.” “My husband used to bring me flowers every week –even when times were hard and we didn't have much money. Those were wonderful days; he was very romantic and – of course – I miss him after he died.

    I paid for my flowers as she was gathering up her groceries. I walked up to her, touched her on the shoulder and said,“You were right, you know. These flowers are indeed for a very special lady.” I handed her the flowers and thanked her for such a nice conversation.

    It took her a moment to realize that I was giving her the flowers I had just bought.“You have a wonderful evening,” I said. I left her with a big smile and my heart warmed as I saw her smelling the beautiful flowers.

    I remember being slightly late for my date that night and telling my girlfriend the above story. A couple of years later, when I finally worked up the courage to ask her to marry me, she told me that the story I had told her that night helped me win her heart.

    A few years ago, bubble tea(奶茶) exploded as a popular drink for Internet foodies(吃货) everywhere. Many take this Taiwanese drink as a guilt-free snack similar to juice or a cup of coffee. After all, it has the word "tea" in it, so it has to be healthy…right?

    Not quite. Like coffee, bubble tea's ingredients(成分，配料) might not be so bad on their own, but when they're loaded with sweetener(甜味剂) and artificial flavor(人工香料), they lose their nutritional (营养的) value fast.

    It all starts with those "bubbles" found at the bottom of your drink, which are actually round pieces of tapioca(木薯淀粉). Called "tapioca pearls(珍珠)," they're actually made from a vegetable that grows in South America. And as it turns out, those little balls are loaded with sugar—and not the nutritious, fiber-rich(富含纤维) kinds found in whole grains(全麦类), either.

Cooking tapioca pearls only makes it worse. They're typically fried in hot water, along with even more added sugar, for up to three hours. By that point, these balls could have nearly 160 calories per ¼ cup.

    And don't even get us started on what comes in the extra syrups(糖浆). Thanks to all those processed(加工的) ingredients, the average bubble tea can easily reach 300 to 400 calories per cup!

    On top of being an unhealthy habit, bubble tea could even shorten your life. In 2012, a group of German researchers from the University Hospital Aachen reportedly found aspolychlorinated biphenyls, or PCBs, in tapioca ball samples. These cancer-causing chemicals have also been shown to have other bad effects on the immune(免疫), reproductive(生殖), and nervous systems.

    You might want to lay off your bubble tea addiction. Thankfully, we have a few choices for low-calorie, healthier drinks, instead.

    Every time your fingers touch your cell phone, they leave behind trace of amounts of chemicals. And each chemical offers clues to you and your activities. By studying them, scientists might be able to piece together a story about your recent life, a new study finds.

    A molecule (分子) is a group of atoms. It is the smallest amounts of some chemicals. Your skin is covered in molecules picked up by everything you touched. With each new thing your skin contacts, you leave behind some small share of what it'd touched earlier.

    Researchers at the University of California, San Diego (UCSD) recently studied such chemical leftovers on the phones of 39 volunteers. The study was led by biochemist Amina Bouslimani. To explore those residues (剩余物), the UCSD team wiped the surface of each volunteer's phone with a cotton swab (药签). The scientists also swabbed each person's right hand. Then the researchers compared the chemicals found on each cell phone.

    The scientists discovered as many of the molecules as they could. They then compared those to a database of chemicals. Pieter Dorrestein, a UCSD pharmaceutical chemist, had helped set up that database a few years earlier, which contains various substances, including spices, caffeine and medicines.

    Traces of everything from hundreds to thousands of different molecules turned up on each phone. The molecules suggested what had been in the body, and what each person had handled before touching the phone. From all these molecules, Bouslimani says, “We could tell if a person is likely female, uses high-end cosmetics (化妆品), colors her hair, drinks coffee, prefers beer over wine or likes spicy food.”

    Police already use molecular analyses to look for traces of explosives or illegal drugs. To date, Dorrestein says, he's never heard of police using phone residues to narrow down behaviour clues to search for a suspect. But detectives might one day use such data to track down someone who left a phone behind at a crime scene.

    A good modern newspaper is an extraordinary piece of reading. It's great first for what it contains：the range of news from local crime to international politics, from sports to business, from fashion to science, and the range of comment and special feature(特写) as well, from editorial page to feature articles and interviews to criticism of books, art theatre and music.

    A newspaper is even greater for the way one reads it：never completely, never straight through, but always by jumping from here to there, in and out, glancing at one piece, reading another article all the way through, reading just a few paragraphs of the text.

    A good modern newspaper offers a variety(多样性) to attract many different readers, but far more than the reader is interested in. What brings this variety together in one place is its topicality(时事性), its immediate relation to what is happening in your world and your locality now. But immediacy and the speed of production that goes with it also mean that much of what appears in a newspaper has no more than transient(短暂的) value.

    For all these reasons, no two people really read the same paper：what each person does is to put together, out of the pages of that day's paper, his own selection and order, his own newspaper. For all these reasons, reading newspapers efficiently, which means getting what you want from them without missing things you need and without wasting time, demands skill and self-awareness as you change and apply the techniques of reading.