Everyone knows that if a dog's ears are up and its tail is wagging vigorously, it is definitely pleased to see you. but now scientists using a robot have found that the way dogs use their tails is more complicated than we thought, and that dogs which wag them to the left may he more friendly. The animal psychologists discovered that when real dogs approached a life-sized robot dog, they were less cautious about it when it was wagging its tail to the left, while if it was wagging its tail to the right, far fewer dogs approached it in a confident manner.

    In the first experiments, 56 percent of the animals approached the model without hesitation when the tail was wagged to the left, while only 21 percent did so in the other situation. When the researchers excluded (排除) owners from being present, the result were: 31 percent of the dogs approached continuously when the tail was wagging to the left, while only 18 percent did so when it was on the right.

    Animal psychologist Roger Mugford said it added to the growing evidence that does were even more complicated communicators than the animals more closely related to man such as monkeys. He said, “We know that dogs, in a sense, have languages, but it is more complicated because it is not just them wagging their tails, but also giving out chemical displays.”

    He adds, “The research confirms earlier studies suggesting that dogs, like humans, had a left-side preference. If you are going to present a signal to a dog, it is sensible to put it on your left-hand side because that is where dogs, unlike most other animals, tend to look. It is another example of the similarity between dogs and humans. They are a lot more human than we give them credit for.”

    If you are given only 1 yuan, could you live in a city for one day? It seems this may be a little difficult. But students from Xi'an did it.

    On April 10, more than 60 students from the Middle School Attached to Northwestern Polytechnic University took part in the One Yuan Metropolis Survival. The charitable organization for teenagers called Imperceptible Education held this activity. Students not only have to live, but they also have to deal with a lot of hard tasks. It has happened in eight cities and is going to four others, including Beijing, in June.

    To make money, many students looked for part-time jobs and saw how hard life was. Zhang Queue, 14, asked more than 10 restaurants for a job and finally got one chance. “We were sad when they said no. But gradually (逐渐地), we got used to it,” he said. After being a waiter for an hour, he got 25 yuan.

    Some made use of their talents by singing and dancing in parks or shopping malls. Many people who walked by took notice and helped them. Zhao Jincheng, 14, drew pictures and made paper crafts(手工). “This showed it's important to learn a special skill,” he said.

    Living was hard, but finishing the tasks wasn't any easier. They went to different places to finish tasks in a short time. The most amazing one was when they had to exchange things worth thousands yuan with only a piece of paper in half an hour. “We learned how to persuade others. From a balloon to a cake to a bottle of yogurt (酸乳) … after almost 20 tries, we got an expensive necklace,” he said. They will give all of the money they made to poor schools in Tibet.

    “Why do birds sing?” I asked a group of children. “To attract metes(配偶)!” answered a boy. A 4-year-old girl added shyly, “birds sing because they are happy, and they want to make us happy, too.” I think both answers are probably true in a way. If birds sing happily, it shows all is well in the forest: no predators (捕食者) are present, and the birds can feed, sing and do other bird things. The sound of a relaxed robin(知更鸟) singing is easy to understand because it makes us feel this way too—it's a sound that lifts our own hearts when we hear it.

    What happens when a predator comes into their areas? The nearby birds quickly give an alarm call, a short sound that warns, “Danger is coming!” On hearing the sound, the other birds stop singing and fly for cover, the deer lift their heads and stop moving and the rabbits run into the bushes. Suddenly, the forest becomes silent.

    When humans walk through the woods in a hurry or while talking with a friend, we don't see much wildlife. We may think that there aren't many animals living there, but more likely, they know we are coming and hide minutes before our arrival. But if we learn to avoid setting off alarms, we can see many more wild animals without frightening them. To practice, find a place in a park and sit quietly for an hour. Take note as the birds begin to relax and sing again. When I do this, I am always surprised at the wonderful thing animals will do when humans simply stay still long enough.

    Have you ever heard a rumor spread around by students at your school? Rumors, like fake news, can often misinform individuals and lead them to believe false information.

    In an attempt to settle this problem, the country of Singapore has passed a bill that bans companies and individuals from publishing false information online.

    This law, known as The Protection From Online Falsehoods and Manipulation Bill, has caused a public outcry (强烈的抗议), as the government has been given the power to remove content that it considers inaccurate or against the public's interest.

    Since Singapore's citizens are part of different racial and religious groups, the government fears that rumors or fake news can increase tensions within an already small country.

    With the new law coming into effect, Singapore's government now has the authority to monitor news sites, social media platforms, and other databases of information to determine whether the content is falsified. The government can order for the removal of fake news, and publishers of this information can receive prison time and fines up to one million Singapore dollars!

    Critics fear that the bill threatens their freedom of speech and freedom of expression. Since national issues and world news are generally discussed on online platforms, many are concerned that this new bill will prevent individuals from talking freely and having healthy conversations.

    Several companies, including Google, Facebook, and Twitter, have offices situated in Singapore, meaning that the new law will affect their company operations. Social media companies in Singapore could face a decline in activity, as users may fear posting their opinions and being punished by the government.

    Others are concerned that the law does not clearly state what a "false statement" is. Such an ambiguity might allow the government to misuse their power, even though the intention is to curtail the mow of false information and rumors throughout Singapore.

    This law does give rise to several concerns related to freedom and privacy and it will be interesting to see what Singapore's government will do to deal with this problem.

Adults check their phones, on average,360 times a day, and spend almost three hours a day on their devices in total. The problem for many of us is that one quick phone-related task leads to a quick check of our emails or social media feeds, and suddenly we've been sucked into endless scrolling.

It's an awful circle. The more useful our phones become, the more we use them. The more we use them, the more we lay neural（神经的） pathways in our brains that lead to pick up our phones for whatever task is at hand-and the more we feel an urge to check our phones even when we don't have to.

What we do know is that the simple distraction of checking a phone or seeing a notification（通知）can have negative consequences. This isn't very surprising; we know that, in general, multitasking does harm to memory and performance. One of the most dangerous examples is phone use while driving. One study found that merely speaking on the phone, not texting, was enough to make drivers slower to react on the road. It's true for everyday tasks that are less high-risk, too. Simply hearing a notification "ding" made participants of another study perform far worse on a task-almost as badly as participants who were speaking or texting on the phone during the task.

It isn't just the use of a phone that has consequences-its me re presence can affect the way we think.

In one recent study, for example, researchers asked participants to either put their phones next to them so they were visible（like on a desk）, nearby and out of sight（like in a bag or pocket）, or in another room. They were found to perform far better when their phones were in another room instead of nearby-whether visible, powered on or not.