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 doctor 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(应用) on your phone, so developers could, for example, create a game controlled by your toothbrush. You could score points for beating monsters(怪物) among your teeth. “We try to make it smart but also fun,” Serval 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, depending 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.

    You may know the Eiffel Tower as one of the most famous man-made monuments in the world, and you'd be absolutely right! Read on to learn about the history of the great Eiffel Tower.

    Travelers from around the world flock(蜂拥)to Paris, France, to visit the Eiffel Tower, making it the most visited paid monument in the entire world! In fact, in 2010, the Eiffel Tower welcomed its 250 millionth visitor!

The history of the Eiffel Tower

    The Eiffel Tower was named after the engineer Gustave Eiffel, whose company designed and built the famous monument. Construction began in January of 1887 and was completed in only two years. Their plan was to finish the tower in time to be the entrance arch for the World's Fair in 1889. This fair celebrated the 100^th anniversary of the French Revolution, which took place from 1789 to 1799.

The height competition

    Located on the Champs de Mars, the tower is the tallest structure in Paris. It was the tallest man-made structure in the world for 41 years until the Chrysler Building in New York surpassed(超过) it. Then the spire(塔尖) on the top of the tower was added, raising its height to 17 feet taller than the Chrysler Building. It is now 1,063 feet tall! There are two replicas(复制品) of the Eiffel Tower in the world: a half scale model at the Paris Hotel in Las Vegas and a full-sized monument of a similar (but not exact) design in Tokyo, Japan.

Three shades of wonder

    Some pictures make the Eiffel Tower look like a dark iron color. But it is, in fact, bronze. Not only that, but the tower is actually painted three different shades to make it appear even taller: darkest on the bottom and lightest on the top.

    Which boy hasn't dreamed of being a cool secret agent (特工)? The wonderful fighting abilities and the world-saving adventures are much more colorful than most people's everyday lives. Well, Cody Banks is just like any other boy, except that he is not just dreaming. He has a big secret his friends never know about. He was trained to be a spy (间谍）by a special CIA programme, which was made to look like a summer camp. He learned high-speed driving, hand-to-hand fighting and the use of high-tech tools.

    After proving he could become a young hero by saving a baby from a runaway car, Banks gets his first real task. He must make friends with a popular girl at school, Natalie Connors. Then, he must spy on her father, a scientist who has developed a dangerous technology (技术).Banks must stop a group of bad people from forcing Natalie's father into using the technology to endanger the world.

    The CIA may have taught him first-class self-defense moves, but they didn't show him how to talk to girls. Banks has zero ability when it comes to dealing with girls. How can he get around his problem and get an invitation to the girl's upcoming birthday party? Will he finally become Natalie's boyfriend and find out whatever he can about her father's work?

    Agent Cody Banks has everything that young people are interested in: big explosions, breath-taking performances and funny girl-dating experiences. It was listed No.2 in the American box office last week.

    “This story is interesting and fun for the whole family to enjoy, and especially cool for young boys，” said Paul Perkins, a film reviewer in the US.

    Last year, Claire Noble-Randall woke up at 5:30 am every morning. She had to catch two buses to arrive in time for first-period chemistry at Ingraham High School in Seattle, US.

    Ingraham starts at 8 am, but Noble-Randall often didn't go to sleep until after midnight. “It was really hard not to fall asleep in class,” she said.

Her mom solved the problem this year when she discovered that other parents had hired a private city tour bus to take their children to the school.

    “Now, she leaves the house at a much more reasonable time 7:10 in the morning…to catch the little tour bug at 7:23 am,” said her mother, Noelle Noble.

    That may be one way to help students get more sleep. But more than 3,300 people have signed an online petition (请愿) looking for a better solution from the Seattle school district. Those who have signed the petition want all high schools and middle schools to start no earlier than 8:30 am. Most of Seattle's high schools and middle schools start at 8 am or earlier.

    Later start times for teenagers is an idea that some parents around the nation, have wanted for years. They've provided plenty of scientific evidence that teenagers tend to be night owls and delayed start times improve their health, mood, attention, and, in some cases, learning.

    But attempts to delay start times for teenagers haven't worked. Coaches don't want late dismissals (放学) cutting into sports practices; community groups don't want to wait longer for gyms and fields and before- and after-school programs don't want to change their schedules.

    This time, however, they've got Seattle School Board. President Sharon Peaslee on their side. She herself is the mother of two high school students. Peaslee hopes other board members will pass her plan calling on the district to find a way to make the changes.

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    The animal kingdom lost a beloved friend when poachers（偷猎者）in Kenya killed the world famous elephant named Satao solely for his ivory（象牙）, experts say.

    Satao was considered by some to be the largest and oldest elephant left in Africa. His tusks having grown long enough to reach the ground. Wandering around Kenya's Tsavo National Park, he was easily recognizable（可辨认的）by staff and visitors. Sadly, despite conservation efforts, he was killed on May 30, his body identified by park staff on June 2. His head was severely damaged and there were two holes left where his great tusks had

    “There is no doubt that Satao is dead, killed by an ivory poacher's poisoned arrow to feed the seemingly greedy demand for ivory in far off countries,” wrote Richard Moller of The Tsavo Trust. “A great life lost so that someone far away can have a trinket（饰品）.

    Satao isn't the first elephant—and far from the last—to pay the ivory price. Just last month, Mountain Bull, another Kenyan elephant, was killed by poachers.

    Kenya Wildlife Service（KWS）says 97 elephants and 20 rhinos have been killed this year, but others say the real numbers are much higher.

    The national park in which Satao lived is roughly 386 square miles—a massive land for already thinly-stretched resources to cover. Reports indicate that Satao had started to migrate towards the park's border-areas known by conservationists（野生保护人士）to be highly active for poaching.

    In the late 1960s, more than 275,000 elephants lived in Kenya. Now, that number has dropped to around 38,000, and continues to fall fast.

    “If Satao's death can cause the focus on what's actually happening here in terms of poaching, then he won't have died in vain,” said nature documentarian Mark Decble, according to The Dodo.

    Your house may have an effect on your figure. Experts say the way you design your home could play a role in whether you pack on the pounds or keep them off. You can make your environment work for you instead of against you. Here are some ways to turn your home into part of your diet plan.

    Open the curtains and turn up the lights. Dark environments are more likely to encourage overeating, for people are often less self­conscious (难为情) when they're in poorly lit places—and so more likely to eat lots of food. If your home doesn't have enough window light, get more lamps and flood the place with brightness.

    Mind the colors. Research suggests warm colors fuel our appetites. In one study, people who ate meals in a blue room consumed 33 percent less than those in a yellow or red room. Warm colors like yellow make food appear more appetizing, while cold colors make us feel less hungry. So when it's time to repaint, go blue.

    Don't forget the clock—or the radio. People who eat slowly tend to consume about 70 fewer calories (卡路里) per meal than those who rush through their meals. Begin keeping track of the time, and try to make dinner last at least 30 minutes. And while you're at it, actually sit down to eat. If you need some help slowing down, turn on relaxing music. It makes you less likely to rush through a meal.

    Downsize the dishes. Big serving bowls and plates can easily make us fat. We eat about 22 percent more when using a 12­inch plate instead of a 10­inch plate. When we choose a large spoon over a smaller one, total intake (摄入) jumps by 14 percent. And we'll pour about 30 percent more liquid into a short, wide glass than a tall, skinny glass.