How long has 3-D technology been around? Most of us might think of crowds of teenagers in a 1950's movie house watching Bwana Devil in 3-D. But 3-D technology made its first appearance on the scene in 1838 with the first stereoscope(体视镜). And the first actual 3-D movie was a 1903 film called Le Ariveed'un Train.

    Although it has such a long history, the technology has still remained based on one simple principle—to make 3-D effects you must find a way to project two slightly different pictures to each eye. Modern 3-D technology works by rapidly flickering(闪动)two versions of the movie and projecting them onto each eye. The brain does the rest of the work, combining the two pictures together into one and giving the show the appearance of depth, the third dimension.

    But does this exposure, especially long exposures, cause harm to the child's developing brain and visual system? Unfortunately, long-term studies on new flicker digital 3-D technology and children aren't yet available. We do not know if regular or daily 3-D viewing over years affects the developing visual system, although older 3-D methods basically do the same thing and are not considered harmful.

    The question of possible harm in modern 3-D use in TV is really based on two facts: the amount of time children will now be watching 3-D TV each day and the sensitivity some children show in reaction to 3-D viewing. It is difficult to make actual lab studies of longer term 3-D viewing in children because of the possible harm of the experiment. Researchers will have to wait until 3-D TV technology is already in the marketplace for a number of years, then check heavy 3-D TV watchers and compare them with non-watchers.

    With a 3-D television technology in the home, we will soon be able to answer the question of whether or not longer and more frequent periods of 3-D exposure cause more changes in the visual system. We may find that the bigger problem is the introduction of a new technology that leads to even more time spent on TV rather than playing outdoors.

    More and more birds are flying to settle at Qinghai Lake, one of the highest inland lakes in China, thanks to the protection efforts of local governments. Covering an area of over 4,000 square     kilometers. Qinghai Lake is also the country's biggest salt­water lake. Located in Northwest China's Qinghai Province, the lake is famous for the two islands at its northwest point—Cormorant Island and Egg Island. The two islands have plenty of floating grass and various schools of fish, offering rich food sources for birds. The islands have become a paradise for different kinds of groups of birds and have been called“Bird Islands”．

    Each March and April, when ice and snow covering the Qinghai­Tibet Plateau starts to melt, over 20 kinds of birds fly to the Bird Islands to lay eggs.  During the months, flocks of birds cover the whole sky over the islands and birds eggs can be found everywhere. Visitors can hear the singing of birds from miles away. These have become a world famous symbol of the lake.

    To protect this paradise for birds and support calls for ecological protection, China set up the Qinghai Lake Natural Protection Zone at the end of 1997.Meanwhile, the State has pointed out the Bird Islands and Spring bay of the Qinghai Lake as central protection zones.

    Inspection officials and management employees often patrol the lake, improving local residents' knowledge of related laws and spreading knowledge about animal protection to visitors. They are making great efforts to call on people to love and protect the birds. At the same time, they have built special fences around the island area to prevent wolves, foxes and other carnivorous animals, as well as illegal hunters from breaking up the birds' nest­building, egg­laying and breeding. As a result, more and more birds are coming to the islands for sheltering and breeding.

    As health care costs continue to rise, a growing number of companies are working out programs designed to keep their employees healthy.

    Thomas Chapple is the senior vice president. “It's really important to us because medical costs are going up like crazy,” he says. “This company spends more than $ 200 million a year on medical costs for its employees around the country. The best thing we have seen as a way to control the medical cost is individual fitness.”

    “We have a fitness center,” Shawn Flaherty, director of public relations for Freddie Mac., says. “We have a health benefits plan that encourages people to work out three times a week, get cholesterol （胆固醇）checks, as well as 'do not smoke.' If they do that, it will cost them less for the health benefits.”

    Rachelle Clark works for Freddie Mac. “I feel great. You know the benefit is rewarding. I like to look good and feel healthy. I am just fortunate that I work for the company that provides some type of facility for the employees.”

    While on-site fitness centers are popular, some companies pay membership fees at local gyms for employees. The companies also offer classes such as boxing, yoga and dancing. Employees see those health programs as a valuable benefit.

    Tom Brook exercises five days a week. As a newspaper reporter he has a tight schedule, although Tom says it's not that difficult for him to make time for a workout. “It is great. It is right here where we work,” says Tom. “So everybody gets a chance to use it whenever they want to. I have lost weight and never been in better shape.”

    The programs may not be a magic cure for rising health costs, but they seem to have a positive impact on both employers and employees.

Why College Is Not Home

    The college years are supposed to be a time for important growth in autonomy(自主性) and the development of adult identity. However, now they are becoming an extended period of adolescence, during which many of today's students are not shouldered with adult responsibilities.

    For previous generations, college was a decisive break from parental control; guidance and support needed to come from people of the same age and from within. In the past two decades, however, continued connection with and dependence on family, thanks to cell phones, email and social media, have increased significantly. Some parents go so far as to help with coursework. Instead of promoting the idea of college as a passage from the shelter of the family to autonomy and adult responsibility, universities have given in to the idea that they should provide the same environment as that of the home.

    To prepare for increased autonomy and responsibility, college needs to be a time of exploration and experimentation. This process involves "trying on" new ways of thinking about oneself both intellectually(在思维方面)and personally. While we should provide "safe spaces" within colleges, we must also make it safe to express opinions and challenge majority views. Intellectual growth and flexibility are fostered by strict debate and questioning.

    Learning to deal with the social world is equally important. Because a college community(群体) differs from the family, many students will struggle to find a sense of belonging. If students rely on administrators to regulate their social behavior and thinking pattern, they are not facing the challenge of finding an identity within a larger and complex community.

    Moreover, the tendency for universities to monitor and shape student behavior runs up against another characteristic of young adults: the response to being controlled by their elders. If acceptable social behavior is too strictly defined(规定) and controlled, the insensitive or aggressive behavior that administrators are seeking to minimize may actually be encouraged.

    It is not surprising that young people are likely to burst out, particularly when there are reasons to do so. Our generation once joined hands and stood firm at times of national emergency. What is lacking today is the conflict between adolescents' desire for autonomy and their understanding of an unsafe world. Therefore, there is the desire for their dorms to be replacement homes and not places to experience intellectual growth.

    Every college discussion about community values, social climate and behavior should include recognition of the developmental importance of student autonomy and self-regulation, of the necessary tension between safety and self-discovery.

    WeChat, the Chinese social media smartphone app, saw an increase in user numbers of 41 percent year on year to 500 million at the end of last year, in a sign that parent company Tencent is extending its reach for the mobile Internet. As one of the largest Internet integrated service providers in Chinaand one of the most Internet users in China, Tencent's profit grew 24 percent to RMB 20.98 billion per year, slightly higher than forecasts, driven mainly by online gaming profits. It is unclear how much WeChat contributed to Tencent's profits but the app's growth is a strong indicator of the company's long-term health as it tries to adjust its business to be more suitable for mobile devices.

    "We extended our leadership in games and online media, and made breakthroughs in emerging platforms such as online security and mobile payments." Ma Huateng, Tencent chairman, said in a statement. WeChat is the second highest ranked social app in China, behind QQ, Tencent's another chatting app, which claimed to have 815 million registered monthly users at the end of 2014.

    Tencent has been unwilling to earn money through WeChat by flooding it with advertising, which could influence the users' experience. But this is expected to change. Some analysts anticipated(预期) that advertising would be introduced on a large scale later this year. Early attempts to test ads on the service have not always gone smoothly. After a BMW ad was introduced on some users' feedbacks in January, many users who were not targeted by the brand's marketing complained of "discrimination" by Tencent's data mining algorithm(数据挖掘算法). They claimed it unfairly treated them as not wealthy or successful enough to view the BMW ad.

    TV, iPads, and computers are fun and sometimes educational, but many people think the technology is bad. My parents let me watch one or two shows or play a game on the iPad for an hour, but then make me find thing else to do, like read or draw a picture. They say that too much screen time won't help me become smarter.

    I think that it is okay to watch TV, but not too much. And some of my friends agree.

    "A tiny bit of screen time is okay," Mateo J., 7, said. "But too much of it is not good for your brain."

    Though my friends and I sometimes complain (抱怨), we think that it's good our parents limit our screen time.

    "Our parents should limit our technology time because otherwise you might get carried away and not even know that you've stayed inside all day watching TV," Naomi J. , 9, said.

    The American Academy of Pediatrics(AAP) used to recommend (推荐) that parents let kids have about two hours of screen time per day, but in 2016, they started recommending that parents of kids 6 and older decide for themselves how much time is okay, as long as the shows and games are appropriate. The AAP still says that kids 2-5 years old should have only about one hour of screen time per day, and kids under 2 no screen time at all. The AAP says that media you've stayed inside all day in all forms, including TV, computers, and smartphones, can affect how children feel, learn, think, and behave. However, parents are still the most important influence.

    I think TV shows like Brain Games and Cupcake Wars are inspiring. I've even learned some magic while watching Brain Games! Video games can be educational, as some TV shows are about nature, and other shows have useful messages. But some games and shows have bad things in them, like smoking.

    You can play outside instead of watching TV. Find other things to do. You don t have to be or screens all day.