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.

    Most people who fly on passenger planes in the United States do not lose their luggage. Even if the luggage is lost, usually it is only delayed. Most “lost” luggage is found in a few days. Airlines search for the owners of unclaimed(未认领的) bags for up to three months. But when the owners cannot be found or the bags are not claimed, they are sold to a store in the small city of Scottsboro, in the southern state of Alabama.

    About one-half of one percent of all luggage passing through US airports is unclaimed. Many of the missing bags, and what is in them, are sold at the Unclaimed Baggage Center. Seven thousand items arrive at the store every day. Tom Barnes, who was shopping at the store said, “I can go into any of the large shopping centers, like the international malls. I can walk through there for an hour and come out with three items. But I come into this store, and then I come out with my car full of stuff.”

    Brenda Cantrell, who works at the store, said, “The Unclaimed Baggage Center is the only store in America that buys and resells unclaimed baggage from the airline industry. You would be surprised at all the jackets, eyeglasses, neck pillows, blankets, laptops, Kindles, iPads, and you know, all kinds of expensive electronics.”

    The store says it once sold a container for flowers for $80 that was found to be worth $18,000. And it says a painting it sold for $25 was later found to be worth $25,000.

    The store buys the luggage from the airlines. It does not examine the things inside them before buying them. Only about half of the items in the bags are suitable for sale at the store.

    Some people say it is not fair to the owners of the lost passage to sell their goods. Customer Daniel Martin is not one of them, saying, “I feel the airport may try to find the people that lose the things. If they've tried and they can't get a hold of them, it's better than throwing them away or just letting them rot in a warehouse somewhere.”

    In the U. S. state of Washington, a road called Interstate(州际公路；州际的)90 cuts through a wild mountainous area to reach the city of Seattle. For the area's many kinds of animals, busy high- way greatly limits their movements. Animals need to move to find food, to find mates, to find new places to live as their populations expand or just when conditions change, like a fire breaks out. Crossing I-90 – as the road is called – is a risky but sometimes necessary act. But soon, animals will have a safer choice. They will be able to go above it.

    To help the animals, the state is finishing work on its largest - ever wildlife bridge. The 11-meter-tall, 20 - meter - wide bridge begins in the forest. It forms two arches above the highway, one for each direction of traffic. Workers are adding fencing anti plants to help guide the animals across the bridge, Two-meter-thick walls will help block noise from vehicles below. Scientists chose the area because it is within a natural migration(迁徙)path for some animals.

    The I -90 bridge is part of a growing number of wildlife crossings across the United States. Some are fences, some are overland bridges，and some are underpasses. They all aim to keep drivers and animals away from each other.

    A U. S. Transportation Department study found crashes between animals and humans rose year by year. The accidents made up about 5 percent of all crashes nationally, and cost the economy (经济)about ＄8 billion. Such costs come from car repaid, emergency room visits and removal of the dead animals on roads. Collisions between animals and drivers are rarely deadly to people. But they are often deadly to wildlife. The study also found that 21 endangered or threatened species in the U.S. are affected by vehicle hits. Bridges, underpasses and fencing reduce I he area's animal - driver collisions by 80 percent.

    Most of the wildlife bridges are in western states. Many other areas also need such paths. But finding money for more crossings is "the- number - one problem". Patty Garvey — Darda of the U. S. Forest Service has worked on the I - 90 crossing from the start of the project. She says the $ 6 - million bridge will one day pay for itself because the highway will not have to be fully or partly closed each time a large animal is struck. "If you shut clown Interstate 90, you shut down interstate trade." she adds.

    The clock always seems to be ticking rather too fast in the doctor's office and the queue of patients outside the door seems to be pressing rather too hard. Some say it's high time for the model of short, sharp one-to-one appointments to give way to shared medical appointments (SMAs).

    SMAs are doctor-patient visits in which a group of patients receive patient education and counseling (咨询),physical examination and medical support in a group setting. Typically SMAs are designed to have one or more doctors attend to a group of patients who share a common illness or medical condition. In contrast to one-to-one visits, SMAs provide a longer appointment time-frame as well as the opportunity for patients to have improved access to their physicians and meanwhile pick up additional information and support from peers.

    However, doctors who have pioneered the shared appointment approach report that there are significant challenges involved. Dr. Sumego, director of shared medical appointments, Cleveland Clinic, identifies culture change as the most significant challenge. Physicians and nurses are trained in a model of personal service and privacy; the SMA approach is a fundamental challenge to those fixed ideas. They need shared goals and a way of testing the innovation against agreed standards. Dr. Sumego says, "The physicians may be worried about the possible chaos and efficiencies that are marketed. They also have to make the patients understand what their appointment is, and what the expectation is."

    "So, if an organization was looking to start shared medical appointments, I would advise them to start the buy-in from a few champion physicians, develop the work-flow and develop some experience. Provide some support behind what that best practice should look like. Create some standards so that, as the concept spreads, you can employ that experience to start the next shared medical appointments and the next."

    The United States estimates that about one out of every 10 people on the planet today is at least 60 years old. By 2050, it's projected to be one out of 5. This means that not only will there be more old people, but there will be relatively fewer young people to support them.

    Professor Richard Lee of the University of California at Berkeley says this aging of the world has a great effect on economics. "Population aging increases the concentration of population in the older ages and therefore it is expensive," he said.

    Aging populations consume (消耗) more and produce less. With more people living longer, it could gel expensive. But Mr. Lee says with continuing increases in worker productivity and wise planning, it can be manageable.

    Societies have different methods for caring for the elderly，but each carries a cost Generally, there are three types of support Seniors can live off the wealth they gained when they were younger. They can rely on their family to take care of them, or they can rely on the movement.

    In industrialized nations, governments created publicly-funded (公共资助的) support systems. These worked relatively well until recent years, when aging population growth in places like the United States and Western Europe began to gradually weaken the systems' finances(资金). These nations now face some tough choices. Mr. Lee says the elderly in some of these countries must either receive less money, retire later or increase taxes to make the system continuable.

    Most developing nations haven't built this type of government-funded support, but have instead relied on families to care for their elderly. These nations also generally have a much younger population, which means their situation is not as urgent as more developed nations. But Mr. Lee says that doesn't mean they can pay no attention to the issue. "Third World countries should give very careful thought to this process, to population aging and how it may affect their economies — now, before population aging even becomes a problem," he explained.

    The love story between John F. Kennedy and his wife, Jackie, was far from perfect and was tragically cut short in 1963 by a sniper's(狙击手) bullet.

    On November 22, 1963, President John F. Kennedy was seated beside his smartly dressed wife, who was wearing a pink Chanel-like suit and matching pillbox hat and holding an armful of red roses that had been presented to her by fans. They were seated in the back seat of a dark blue 1961 Lincoln with John Connally, the Governor of Texas and his wife, Nellie.

    And then came the dark moment. As the motorcade(车队) passed the Texas School Book Depository on Elm Street, a loud noise—like the sound of a firecracker—cracked the air. President Kennedy slumped(耷拉) forward, Jackie putting her arms around him.

    The look on her husband's face after he was shot would haunt Jackie for the rest of her life. The last words she ever got to say to him were, "I love you, Jack. I love you," according to Anderson, although Jackie herself recalled it slightly differently in a 1963 interview. All the way to Parkland Hospital, where President Kennedy would eventually be pronounced dead, as she recalled it, she was bent over him, asking "Jack, Jack, can you hear me? I love you."

    Jack Kennedy's final words to his wife of 10 years were far more mundane, of course. He had no way of knowing what was about to happen. It's been reported that Jack's final words were, "My God, I've been hit," but physicians have said this was impossible given Jack's injuries. Well, historians have now clarified that the last words Jack spoke before the fatal shot were, "No, you certainly can't."

    No, you certainly can't?

    He was making small talk in the car. "You certainly can't say that the people of Dallas haven't given you a nice welcome," the Texas Governor's wife had just remarked to Jack, referring to the huge, adoring crowd. "No, you certainly can't," Jack replied, milliseconds before the bullet from Lee Harvey Oswald gun struck.

    John F. Kennedy never spoke another word after that fateful day, but many things he said during his lifetime are incredibly inspiring.