For a year and half, kids sent hurtful messages like “You are ugly.” or “Why are you still alive?” to Rebecca Sedwick. In 2013, Rebecca, then 12, couldn't stand it anymore. She took her own life near her home in Florida. Soon afterward, Trisha Prabhu read about the story. “I was surprised and heart-broken,” said Trisha, now 15, who is from Naperville, Illinois, “I know that I had to do something to stop this from ever happening again.”

    Trisha did some research. Studies show that one fourth to half of all teens in the US have been cyberbullied (网络欺凌). Experts say that if you are ever bullied online, you should tell a trusted adult. Tell the cyberbully to stop, and prevent him or her from contacting you again. Print and save messages to share with the police. This is good advice, agrees Trisha. But these methods all take place after the bullying has already happened. Trisha had a different idea. Why not teach cyberbullies to stop before they post these messages?

    Trisha's research won awards, including a prize in the Google Science Fair. Then, Tresah built the ReThink app (应用软件). It is programmed to recognize words or phrases that could be hurtful. When that happens, different warning messages come out. “Don't say things that you may regret later!” says one message. Others ask, “Are you sure you want to say this?” and “Are these words really yours?”

    Now Trisha is working on a version(版本) of ReThink for computers. “I am a big dreamer,” she says. “I want to stop cyberbullying before the hurt is done.”

    Cheating can happen in a lot of different ways. When people cheat, it's not fair to other people, like the kids who studied for the test or who were the true winners of a game.

Many people like the action of cheating. It makes difficult things seem easy, like getting all the right answers on the test. But it doesn't solve the problem of not knowing the material and it won't help on the next test — unless the person cheats again.

    Some people lose respect for cheaters and think less of them. The cheaters themselves may feel bad because they know they are not really earning that good grade. And, if they get caught cheating, they will be in trouble at school, and maybe at home, too.

    Some kids cheat because they're busy or lazy and they want to get good grades without spending the time studying. Other kids might feel like they can't pass the test without cheating. Even when there seems to be a “good reason” for cheating, cheating isn't a good idea.

    If you were sick or upset about something the night before and couldn't study, it would be better to talk with the teacher about this. And if you don't have enough time to study for a test because of swim practice, you need to talk with your parents about how to balance swimming and school.

    A kid who thinks cheating is the only way to pass a test needs to talk with the teacher and his or her parents so they can find some solutions together. Talking about these problems and working them out will feel better than cheating.

    If you're new to San Francisco, paying the city a visit, or simply looking for a new playground for you and your dog, here are four of the finest dog parks in San Francisco.

    Corona Heights Dog Park

    Often visited by residents from all over the city because of its nearness to the Randall Museum, Corona Heights Dog Park offers pets and owners breathtaking view after a steep hillside climb, and a fenced dog area that allows dogs to let loose without a leash（狗链）. Owners will also enjoy the playground, tennis courts and basketball courts.

    Dolores Dog Park

    The grounds of Dolores Park once served as camps for those who were left homeless by the 1906 earthquake, but now are often visited by crowds of Mission District people. Four-legged friends can also wander about carefree off-leash while making friends with other members of the doggie community.

    Pine Lake Dog Park

    Famous for its place as a rest stop for hundreds of species of birds to fly to and from warmer climates, Pine Lake Park is also prized by city dogs and their owners for their nice hiking paths, picturesque lake suited for swimming, and off-leash area on the park's west end that lets dogs run free.

    Buena Vista Dog Park

    With a history of 146 years, Buena Vista Park is San Francisco's oldest park. Dogs and owners with plus energy will love burning it on this park's steep paths and winding staircases. Dog owners should have good control over their dogs, as it's quite easy for dogs to get separated when going through Buena Vista's many twists and turns.

    It is becoming increasingly important for researchers to closely monitor our ocean life. However, observing sea creatures up close is almost impossible since human presence scares them. Now, thanks to The Soft Robotic Fish, also known as SoFi, researchers may be able to keep a close eye on the sea creatures.

    Built by MIT Computer Science and Artificial Intelligence Laboratory (CSAIL), the white re- mote-controlled robot resembles the real fish, complete with a tail that waves from side to side. Though not the first autonomous underwater vehicle (AUV) created to monitor the ocean, SoFi settles many of the problems that have blocked the usefulness of the previous robot fish.

    Previous AUVs have had to be linked to boats because radio frequency communications don't work well underwater. To overcome the problem, Director of the CSALL Daniela Rus and her team used sound waves. The technology can travel greater distances allowing divers to pilot SoFi from up to 50 feet away.

    Also limiting the usefulness of traditional AUVs is the risk of collision. With the outside made of soft silicone (硅树脂) rubber and flexible plastic that keeps its inbuilt electronics dry, SoFi poses no such danger. "Collision avoidance often leads to unnecessary movement, since the robot has to settle for a collision-free path", says Rus. "In contrast, a SoFi robot is not only more likely to survive a collision but also could use it as information to form a more workable movement plan next time around."

    During test dives, SoFi moved alongside the ocean life at depths of 50 feet for up to 40 minutes at a time, taking photos and making videos. The researchers say sometimes the fish would swim a- longside the strange-looking robot-fish out of curiosity, while at other times they took no notice of its existence.

    While SoFi presently only records video, future versions will include sensors. The researchers also hope to make it more autonomous. "We imagine someday it might help us uncover more secrets from the amazing underwater world that we know so little about," says Rus.

    When an earthquake hit a small town, many houses fell down. After the earthquake, all the newspapers reported many stories about some of the families who were in trouble.

    One Sunday, when I was reading a newspaper, a special picture touched me. It gave the clothing sizes of each family member. I thought that this would be a good chance to teach my children to help those who were less lucky than themselves. I said to my seven-year-old twins, Brad and Brett, and three-year-old Meghan, "We have so much, and these poor people now have nothing. We'll share what we have with them."

    I filled a box with foods and clothes. While I was doing this, I encouraged the boys to choose their toys and donate some of their less favorite things. Meghan watched quietly as the boys took out their old toys and games and put them together. Then she walked away. A few minutes later, she came back with Lucy, her much-loved doll. She put the doll on top of the other toys. "Oh, dear," I said. "You don't have to give Lucy. You love her so much." Meghan said, "Lucy makes me happy, Mommy. Maybe she'll make another little girl happy, too."

    I looked at Meghan for a long moment. She taught me a lesson. It's easy to give something that we don't want any more, but hard to give what we cherish(珍爱), isn't it?

Having a regular dentist check-up is as essential for ensuring healthy teeth and gums（牙龈）as regular brushing and flossing. Here's why you should make the trip.

Prevention is better than cure. Regular dental check-ups are recommended to maintain healthy teeth and gums. {#blank#}1{#/blank#} Your dentist will advise you on what's right for you. The aim of a check-up is to nip any problems in the bud, before you experience pain, lose teeth or have other health problems.

You've had a new medical diagnosis. {#blank#}2{#/blank#} For example, high blood sugar levels in saliva caused by diabetes favour bacteria which can cause cavities（蛀牙）. Some medications can cause oral problems ranging from dry mouth to stained teeth.

{#blank#}3{#/blank#} More and more adults are having orthodontic（正畸）treatment to straighten their teeth. Not only does it make a huge difference to your smile, it can also prevent gum disease, which is more likely to take hold if you struggle to clean crooked teeth.

You've got bad breath. Halitosis（口臭）is embarrassing and can sometimes leave a nasty taste in your mouth. You might have a hole in your tooth, an infection or gum disease. {#blank#}4{#/blank#} Your family and friends will thank you for it.

Check for cancer. Dentists don't just look for cavities and unhealthy gums. They can also spot mouth cancer and refer patients to hospital to see a specialist. Cases have risen by 34 per cent in the past decade, according to the Oral Health Foundation. {#blank#}5{#/blank#}.

A.You want to improve your confidence.

B.You think it is time to have some changes.

C.However, early diagnosis can save your life.

D.Certain conditions can affect your oral health.

E.You might just be brushing too enthusiastically.

F.It varies from three months to two years depending on your oral health.

G.Your dentist can give you tips on freshening your breath more effectively.