In cities with rent control, the city government sets the maximum rent that a landlord (房东) can charge for an apartment. Supporters of rent control argue that it protects people who are living in apartment. Their rent cannot increase; therefore, they are not in danger of losing their homes. However, the critics say that after a long time, rent control may have negative effects. Landlords know that they cannot increase their profits. Therefore, they invest in other businesses where they can increase their profits. They do not invest in new buildings which would also be rent-controlled. As a result, new apartments are not built. Many people who need apartments cannot find any. According to the critics, the end result of rent control is a shortage of apartments in the city.

    Some experts argue that the minimum wage law can cause problems in the same way. The federal government sets the minimum that an employer must pay workers. The minimum helps people who generally look for unskilled, low-paying jobs. However, if the minimum is high, employers may hire fewer workers. They will replace workers with machinery. Therefore, other things being equal, the number of workers that employers want decreases. Thus, critics hold the opinion that an increase in the minimum wage may cause unemployment. Some poor people may find themselves without jobs instead of with jobs at the minimum wage.

    Supporters of the minimum wage say that it helps people keep their dignity. Because of the law, workers cannot sell their services for less than the minimum. Furthermore, employers cannot force workers to accept jobs at unfair wages.

    Economic theory predicts the results of economic decision, such as decisions about farm production, rent control, and the minimum wage. The predictions may be corrected only if “other things are equal”. Economists do not agree on some of the predictions. They also do not agree on the value of different decisions. Some economists support a particular decision while others criticize it. Economists do agree, however, that there are no simple answers to economic questions.

    Life is full of funny moments, and not just for humans.

    Over the years, studies by various groups have suggested that monkeys, dogs and even rats love a good laugh. People, meanwhile, have been laughing since before they could talk.

    Jaak Panksepp, a professor at Bowling Green State University, US, said he would not be surprised if positive feelings could be produced in some animals. Dolphins, for example, have long attracted animal researchers because of the complex (复杂的) ways in which they communicate: a rich variety of sounds of different rhythms. A decade ago, researchers studying dolphins at the Kolmarden Wildlife Park in Sweden noticed a set of sounds the dolphins made during play-fighting. They concluded that the purpose of the sound was to suggest that the situation was pleasant and to prevent it from a real fight.

    Panksepp has even seen evidence of joy in crayfish (小龙虾). When given small amounts of drugs such as cocaine (可卡因) in a certain place, they appear to connect that location with pleasure. “Given the chance, they will always return to that place, perhaps in the hope of getting more,” he says. Panksepp wasn't sure it equals the same happiness that humans get from cocaine, but said it “could be in the same evolutionary category”.

    More studies are needed to really understand animals' laughter. Strangely enough, the answers may help with our own desires for cures for mental illnesses. Panksepp's experiments may soon lead to a new antidepressant (抗抑郁) drug that works by using the pathways in the brain behind positive feelings and joy. Perhaps pleasure and laughter in the animal world will help solve the depression in our own species one day.

    Peyto Lake, Canada

    Located in Banff National Park. Canada's first national park Peyto Lake is one of the most wonderful lakes in the world. What makes it truly beautiful is its unique greenish-blue color, and placement in the Canadian Rockies. Named after trail guide Bill Peyto, this lake is located at a height of 1,860m.

    Entry Details: $9.80 adult, $8.30 senior, $4.90 youth, and $19.60 family.

    Best Time to Visit: July, August, and September

    Lake Argentino, Argentina

    Located in the Patagonian province in Argentina, the lake is truly beautiful. Surrounded by glaciers and snow-covered mountains, the lake presents visual delights like none other. With a maximum depth of 500 meters, it's the biggest freshwater lake in Argentina. The lake is famous for fishing.

    Entry Details: $15~$20, changes as per season, but entry for tourists above 70 years of age is always free.

    Best Time to Visit: December to March, and late November

    Lake Baikal, Russia

    Being the world's oldest and deepest lake, Baikal is about 395 meters long, 49 meters wide and 1,637meters deep. It holds more water than the Five Great Lakes of America combined, and is thus the largest freshwater lake globally. Located in the south Russian region of Siberia, a trip to view this lake is a trip of a lifetime!

    Entry Details: No Entrance fee here

    Best Time to Visit; March to April

    Lake Como, Italy

    Considered one of the most beautiful lakes in Europe, Lake Como has attracted tourists since Roman times. Located in Lombardy, Como is one of the deepest lakes in Europe. Surrounded by vil1as and palaces, this lake has attracted some of the wealthiest. Today, many celebrities(名人) have houses here. Here you can enjoy water sports, take a flight over the lake, or try skiing during the winters-every tourist has something he's going to like!

Entry Details: Free

    Best Time to Visit: July and September

    Your next car could have two seats, three wheels — two in front and one in the back and a top speed of more than 100 miles per hour. Elio Motors plans to make such a tiny car named the Elio. Its two seats sit front and back instead of side by side. The driver is positioned in the center with the passenger directly behind.

    The starting price for the car is just $6,800. It has only one door, on the left side, which cuts a few hundred dollars off the manufacturing costs. Having three wheels also makes it cheaper. It has air conditioning, power windows and door locks and an AM/FM radio. More features can be ordered through Elio's long list of suppliers. Elio will also sell the cars directly through its own stores and not through franchised dealers (特约经销商).

    Paul Elio dreamed as a kid that he would one day own a car company called Elio Motors. In 2008, tired of high gas prices, he started working on a car that burns gas in a more effective way. Equally important to him was creating U.S. manufacturing jobs and making the car inexpensive enough to attract buyers who might otherwise be stuck in their old, unreliable cars. “Whatever matters to you, this can move the needle on it,” he said.

    Already, more than 27,000 people have reserved (预订) one. Paul hopes to make 250,000 cars a year by 2016. So far, reservation holders are those who will use the Elio as a second or third car for work. Finally, though, he believes the car will interest high school and college students as well as used-car drivers who want something newer and more reliable.

    Ten years ago, I set out to examine luck. I wanted to know why some people were always in the right place at the right time, while others consistently experienced ill fortune. I placed advertisements in national newspapers asking for people who felt consistently lucky or unlucky. Hundreds of extraordinary men and women volunteered for my research. Over the years I have interviewed them, monitored their lives and had them take part in various experiments.

    In one of the experiments, I gave both lucky and unlucky people a newspaper, asking them to look through it and tell me how many photographs were inside. I had secretly placed a large message halfway through the newspaper, saying, "Tell the experimenter you have seen this and you will win $50." This message took up half of the page and was written in type that was more than two inches high. It was staring everyone in the face, but the unlucky people tended to miss it and the lucky people tended to spot it.

    Unlucky people are generally more nervous than lucky people, and this anxiety affects their ability to notice the unexpected. As a result, they miss opportunities because they are too focused on looking for something else. They go to gatherings concentrating on finding their perfect partners and miss opportunities to make good friends. They look through newspapers determined to find certain types of job advertisements and miss other types of jobs.

    Lucky people are more relaxed and open, and therefore see what is there rather than just what they are looking for. My research eventually showed that lucky people are skilled at noticing opportunities, make lucky decisions by listening to their intuition (直觉), are open to new experiences, and adopt a never-say-die attitude that transforms bad luck into good luck.

    High school biology teacher Kelly Chavis knew smart phones were a problem in her class. But not even the students realized how much of a problem the devices were until Chavis did an in­class experiment.

    For one class period, students used a whiteboard to count every Snapchat, Instagram, text, call that appeared on their phones. Chavis is among a growing number of teachers, parents and health experts who believe that smart phones are now partly to blame for increasing the levels of student anxiety. "One girl, just during the one hour, got close to 150 Snapchat notifications. 150!" she said.

    Jean Twenge, a psychology professor at San Diego State University in California, said it is not a coincidence that youth mental health issues have risen with the number of phones. "This use of phones has led to a loss of sleep and face­to­face interactions necessary for their growth," she said.

    Researchers are still not sure whether phones cause student depression or depression causes phone use. But nearly 60 percent of parents said they worry about the influence of social media on their child's physical and mental health.

    Both schools and parents are starting to take steps to deal with the problem. Many public schools pay outside companies to watch students' social media activity for signs of anxiety. Other schools invite in yoga teachers and comfort dogs to help calm students.