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.

    Put on your sunglasses and enjoy the island, the sun and the blue sea. Malta combines (结合) learning English with the Mediterranean way of life: you will have language course and a great holiday at the same time,

    Your language course    Our school lies in Sliema, only a few meters from the sea, the beach road and cafés. The school is in an old Maltese building. Our teachers use a modern teaching method and you will learn English quickly.

    The leisure (休闲) programmes    Our school and team leaders organize varied leisure programmes. There will be a welcome party on your first day. You will also take part in beach volleyball, and beach parties. Other activities include: Discos, visit to Popeye Village, Water Park, bowling, cinema, ice skating (different prices).

    Accommodation (住宿) Family    You will live in friendly host families that the school has known for years. All families are near the school (20 minutes on foot or by bus).

    Supervision (监督)    Our team of friendly teachers, team leaders and host families will always be there for you. There is also an emergency phone number for parents and students.

    Dear parents, please note that there are periods of time when your children are unsupervised, for example on the way to school. We are happy to discuss any questions you may have. Please contact us by phone or email.

    Hilary Smith belonged to a good family. But by the age of twenty, he had spent all the money the good old family had. He then had some trouble with the bank and was put in prison. He escaped from the prison and ran to Australia without delay.

    Hilary did not like Australia and Australia did not like Hilary. What he could do seemed to be one of two things: die or work. Then he remembered that he was not alone in the world. He had an aunt.

    She was his father's only sister, but his father used to say she brought no glory to the family. Hilary, of course, tried to discover what she had done. It seemed that she had failed to marry a nobleman. Instead, she had chosen a husband who was connected with "trade". Of course as soon as she became "Mrs. Parks", her brother considered her dead. Later on, Mr. Parks died and left her a lot of money; but that did not bring her back to life in her brother's opinion.

    Hilary discovered his aunt's address. Fortunately she remained faithful and honest to him even after she fell ill. So Hilary's star shone again, and soon he moved into her house and lived as comfortably as a sailor who had just reached harbor. He had only about six pence in his pocket.

    One thing was soon clear: his aunt was seriously ill, and nothing could cure her illness. Hilary was very worried. Fate had found a home for him, and was now going to throw him out of it. There was only one thing that could save him: her will.

    "Will?" she said, "yes, I have made one. That was when I was a girl and had not much money. I left all my money to some religious people."

    "Didn't you make another will when you were married?" Hilary asked.

    His aunt shook her head. "No," she said in a low voice, "There was no need. When I finally had a lot of money, I found I had no relations."

    On the next day he went to the public library and examined a book of law. It told him what he already believed. When a woman is married, an earlier will loses its value. A new will must be made. If no new will is made, the money goes to the nearest relation. Hilary knew that he was his aunt's only relation. His future was safe.

    After a few months had passed, Hilary's problems became serious. He badly needed money. He had expensive tastes, and owed a lot of money to shopkeepers. They trusted him because his aunt was rich, but the debt was terrible.

    Unfortunately his aunt did not want to discuss money matters at all. In the end they had a quarrel about the small amount of ten pounds. Hilary was not very angry. He began to wonder about a new problem. Was it kind to want his aunt to live any longer? Was it not better for her to die now? While he was considering what to do, his aunt told him that she was going to send for her lawyer. So she was going to make a new will, Hilary thought. She might leave all her money to someone else. Soon he reached a clear decision. He must do a great kindness to the poor old woman.

    One night when the old servant who had been nursing his aunt went off, he doubled the amount of some medicine. The total amount was too great and it could just put her to sleep forever.

    "Thank you," his aunt took the glass from his hand with a grateful look." I want, more than anything, to sleep, and never to wake up again. Is that what you wish, Hilary? Don't blame me if I have some doubts about what you intended to do. Sick people get these ideas, you know. One thing I ought to explain to you. Mr. Parks never married me. He already had a wife and couldn't marry again. That made your foolish father very angry with me...Well, if I am alive tomorrow, I shall make another will in your favor. If I die tonight, you'll get nothing...No, Hilary, don't try to take the glass away. If you do that, I shall know and I don't want to know. Good night, Hilary."

    Then, very carefully, she raised the glass to her mouth and drank.

    Emily Temple-Wood was 12 years old the first time she was bullied(欺凌) online. They left ugly comments on her Wikipedia and Facebook pages about her looks “that would make my mother's hair curl.” says Temple-Wood, now 22 and in medical school. The reason? “I was a woman on the Internet,” she said.

    Over the years, she considered how she might take revenge(复仇). Then, as a freshman in college, it hit her: “What do misogynists (men who hate women) hate most?” she asked herself. “Women who are productive!” Her solution: For every rude comment she received, Temple-Wood would post a biography(传记) of a woman scientist, and thus, in 2012, Wiki Project Women Scientists was born. She wrote about her heroes, like Barbara McClintock, who received the 1983 Nobel Prize in Physiology or Medicine, and Caroline Still Anderson, one of the first African American women to become a doctor in the United States, in the late 1800s. With help from other women, many of them scientists who have also been bullied online, Temple-Wood has published hundreds of these biographies and women of all ages have taken notice.

    “When I was a kid, I could count the number of women scientists I knew about on one hand,” wrote Siko Bouterse, who used to work for the Wikimedia Foundation. “But our daughters have the chance to get much more knowledge about scientists who look like them because of Emily.

    The ugly comments still come, says Temple-Wood. Being a strong woman online is not easy. “We all have days when we break down and need to have a glass of wine,” she says. “I tell people who are being bullied that it's OK to be sad. But now you need to find a productive way to take revenge.”

    One of my favorite hobbies is exchanging old-fashioned, paper-with-a-stamp-on-it postcards with random strangers around the world.

    The Postcrossing Project was created by Paulo Magalhaes in 2005. He liked getting mails—especially postcards. He thought others did, too—but how could he connect with them? That's when he came up with the idea of an online platform (postcrossing.com): There, postcard lovers like me can sign up to send a postcard to someone who has registered online, and receive a postcard in return.

    Along with a randomly selected address, participants get a unique code to put on the postcard. When the postcard arrives, the recipient registers that code with the site, which then causes the sender's address to be given to another postcrosser in turn. In practice, this means that for nearly every postcard I send (a few get lost in the mail) I get one back. And since I never know who will send me a card or where in the world they live, every trip to the mailbox holds the potential for a wonderful surprise.

    Privacy-conscious Americans might worry about sharing their address with strangers overseas. But postcrossers are friendly, polite, respectful folks—in more than 450 cards exchanged, I've yet to have a bad experience.

    On days when the international news is depressing, postcrossing is my comfort. There's nothing like getting a card from a child in China just learning to write in English, or a grandmother in Belarus describing her most recent gardening success to remind me that we truly are members of one global family, far more similar than we are different.

    It seems like such a small thing to send out a postcard. But as travel and communication technology continue to shrink the world, it's important to remember that it isn't just for diplomats and politicians to represent our country anymore. All of us have the power—and perhaps the responsibility—to be ambassadors, to show the best of your country to the world.

    And it's good to know that what you need to accomplish this is not necessarily complicated or expensive. It can be as simple as a postcard.

A lunar crystal (水晶) was found in lunar basalt particles (玄武岩颗粒) collected from the moon in 2020 when the Chinese moon mission landed in Oceanus Procellarum, returning with more than 1.7 kg of lunar samples delivered safely to the Earth. 

The crystal found on the near side of the moon is giving scientists hope of providing limitless power for the world forever. It is made of material previously unknown to the scientific community and contains a key ingredient for the nuclear fusion (核聚变) process, a form of power generation that uses the same forces that fuel the sun and other stars. It is transparent and roughly the width of a single human hair, and it formed in a region of the moon where volcanoes were active around 1.2 billion years ago. 

One of the primary ingredients found in this crystal is helium-3 (氦-3) , which scientists believe may provide a stable fuel source for nuclear fusion reactors. The element is incredibly rare on the Earth, but it seems to be fairly common on the moon. China's next moon mission is expected to be carried out by Chang'e 6 in 2024, which will attempt to collect the first samples from the far side of the moon, which never faces the Earth. 

Although it is too early for scientists to have made financial estimates on such a fuel source, it will undoubtedly be extremely costly. There is, of course, the matter of bringing the crystals back from the moon, especially in large amounts that are needed to fuel fusion reactors. 

Helium-3 produces significantly less radiation and nuclear waste than other elements. The current nuclear fusion process has raised serious safety concerns, and as a result, scientists have been searching for a way to create nuclear power from nuclear fusion. During the fusion process, radioactive waste is not produced, potentially making a securer and more efficient fuel source. 

Around 25 tons of helium-3 could power the US for a year. Multiple private companies and countries with space agencies have signaled their intentions to mine the moon for helium-3, and this latest discovery could kick start the race.