Do you believe that things are connected for no scientific reason at all? For example, do you avoid saying the word "four" to avoid bad luck? If so, you have a superstition (迷信). And you're not alone – all kinds of people have them.

For example, Portugal's soccer superstar Cristiano Ronaldo always steps onto the pitch (球场) with his right foot first, according to The Telegraph. And sports players are not alone in having superstitions. A visitor once asked the Nobel Prize winning scientist Niels Bohr whether he really believed that the horseshoe he'd hung at his country home was lucky. "Of course not," the Danish physicist said. "But I understand it's lucky whether you believe in it or not."

One recent study found that even scientists at MIT and other top US schools tended to look for a meaning in natural events, similar to the connection between stepping on the pitch and playing soccer well, according to The Atlantic. When the researchers gave the scientists little time to answer questions, they were twice as likely to agree with statements such as "Trees produce oxygen so that animals can breathe" as they were when they had more time to think about their reply.

It seems that fear can make people think differently in this way, too. In a British study, students imagined meeting a "witch" who said she would cast (施魔法) an evil spell(符咒) on them. About half said a scientist should not be worried about the spell. Yet each of them said that, personally, they wouldn't let the witch do it to them.

So why are so many of us superstitious? Well, it seems to be our way of dealing with the unknown. "Many people quite simply just want to believe," Brian Crank, a professor of psychology at Missouri Western State University, said in a 2008 interview. "The human brain is always trying to work out why things happen, and when the reason is not clear, we tend to make up some pretty bizarre (古怪的) explanations."

    And these explanations aren't completely unhelpful. In fact, superstitions can sometimes work and bring real luck, according to psychologists at the University of Cologne in Germany in the May 2010 issue of the journal Psychological Science. They found that believing in something can improve performance on a task like an exam.

    So, what about you? What superstitions do you follow to keep you safe and successful?

    I was born in England, but I am an American. Americans like to travel on their yearly holiday. Today, more and more travelers in the United States are spending nights at small houses or inns (客栈) instead of hotels. They get a room for the night and the breakfast the next morning.

    Rooms for the night in private homes with breakfast have been popular with travelers in Europe for many years. In the past five to ten years, these bed­and­breakfast places have become popular in the United States. Many of these America's bed­and­breakfast inns are old historic buildings. Some bed­and­breakfast inns have only a few rooms; others are much larger. Some inns do not provide telephones or televisions in the rooms; others do.

    Staying at a bed­and­breakfast inn is much different from staying at a hotel. Usually the cost is much less. Staying at an inn is almost like visiting someone's home. The owners are glad to tell about the areas and the interesting places to visit. Many vacationers say they enjoy the chance to meet local families.

    I was waiting for my train and on the subway station's floor was a man just sitting there. I looked around and nobody stopped so I just went my way. After a few steps, I turned and asked him whether he needed help. He told me his house was one station further and he would only need to take the train there. So I reached for his hand to help him stand up.

    He wanted to take the stairs but I feared that he would hurt himself since he seemed too weak to walk, so I asked him to take the elevator. Even though my mind was trying to turn the danger lights on, I put the thought that I should not go alone with a drunken man out of my mind and accompanied him on the elevator.

    We arrived on the platform with no incidents. The man's knees seemed to soften, so I asked him to rest on a bench. While sitting there, he thanked me, telling me that I saved him. No, I said, I really did nothing; he saved himself as he walked on his own feet.

    At the next station, we said our goodbyes. Before I knew it, he left 100 dollars and dashed out of the train. There was no way to give him back his money. I wanted to leave it on the seat, but a young woman who thought it belonged to me ran after me and gave me the note.

    My initial reaction to getting that money was of shame and I even felt offended. Then I thought he just wanted to thank me, the best way he knew how. Now, my question is — what act of kindness shall I do with these 100 dollars?

Once a blind man fell flat on his face, which was awful but finally harmless. His service dog, however, was trained lo tum to an adult if the owner had an epileptic seizure (癫瘤发作). While the dog did what it was taught, the first person it found was merely annoyed but not alarmed. Thankfully, the dog's owner was not in the situation of medical emergency. But the experience inspired him to share this information on social media, "If a service dog without a person approaches you, it means the person is down and in need of help," the owner explained. "Don't get scared, don't get annoyed, and follow the dog! If the first person doesn't cooperate, it moves on.

Referring to the accident, a TV presenter asked a dog trainer, Olivia, some basic questions about service dogs, including how humans should react if an unaccompanied service dog approaches them.

"What they're going to do is sniff and gently push your leg," the trainer explained, specifically noting that service dogs are not usually trained to jump or bark. "If you see a dog in a vest without a person around it, follow it." When asked if one should say something to indicate they're prepared to follow the dog, Olivia said," there's no clear command. Just start walking wherever the dog leads."

Olivia concluded the TV show by adding that those who rely on service dogs could train their companions to move along to someone else, if the first person the dog came upon reacted negatively to its request. Doing so could finally save the owner's life.

On one side of the room sits the cutest life-size stuffed animal(填充玩具) you've ever seen. On the other side rests a real dog—the same size, shape and even the same name as the stuffed version. You get to sit next to both of these furry friends and pet their fur. Guess which one will make your brain light up?

If you guessed the real dog, you're right. Stuffed animals, as cute and lovely as they may be, just don't effectively activate our frontal cortex(额叶皮层), the part of the brain overseeing how we think and feel, according to a new study published in the journal PLOSONE. The study found an even stronger rise in brain activity when the person petted the fur of a real dog versus a stuffed animal.

"We chose to research the frontal cortex because this brain area is involved in several executive(执行) functions, such as attention, working memory, and problem-solving. But it is also involved in social and emotional processes,"said study lead author Rahel Marti, a doctoral student in the division of clinical psychology at the University of Basel in Switzerland.

Why is this finding important? It provides additional evidence that live human-animal interaction therapy(疗法) may promote cognitive and emotional activity in the brain. Marti said,"If patients with deficits in motivation, attention, and socioemotional functioning show higher emotional involvement in activities connected to a real dog, then such activities could increase the chance of learning and of achieving treatment aims."

"This is an interesting, seriously conducted study that provides new insight into associations between human-animal interaction and regional prefrontal brain activity in healthy adults. We found that brain activity increased when the contact with a real dog or a stuffed animal became closer. This confirms previous studies relating closer contact with animals to increased brain activity,"Marti said.

Earthquake rescue robots have experienced their final tests in Beijing.Their designers say with these robots，rescuers will be able to have more time to save more lives during an earthquake.

This robot，looking like a helicopter，is called the detector bot.It's about 4 meters long，and it took about 4 years to develop the model.Its main functions are to collect information from the air，and send goods of up to 30 kilos to people trapped by an earthquake.

This robot has a high－definition 360－degree panoramic(全景的) camera.It can work day and night and will also be able to send the latest pictures from the quake area.

Dr.Qi Juntong，from the Chinese Academy of Science，said，"The most important feature of this robot is that it doesn't need a distant control.We just set the destination(目的地) information on it，and then it takes off，and lands by itself.It flies as high as 3，000 meters，and as fast as 100 kilometers per hour."

This robot has a different function—it can change as the environment changes.Its main job is to search for any signs of life in places where human rescuers are unable to go.

As well as a detector(探测器) that finds victims and detects poisonous gas，a camera is placed in the 40－centimeter－long robot，which can work in the dark.

Another use for the rescuers is the supply bot.With its 10－meter－long pipe，people who are trapped in the ruins，will be able to get supplies including oxygen and liquids.

Experts have said that the robots will enter production，and serve as part of the national earthquake rescue team as soon as next year.