As I enter my 40s, I've noticed many of my parents' generation think social networking is something they are simply unable to understand. They fear that, should they try, they will somehow get it wrong; they will say the wrong thing, do the wrong thing or behave in a way that causes embarrassment(尴尬). But here's the first secret of social media: Everyone feels this way.

    I recently met a young actor who was complaining that her work demands that she join Microblog, but she always feels like she doesn't have anything smart to say. It's the same resistance (抵制)I hear from the older generation, who, however, have somehow believed that age is the barrier(障碍), rather than the differences of personal taste.

    Here's the second secret of social media: everybody uses it for more or less the same reasons. Older generations often sign up to stay in touch with children and relatives. We talk about this kind of communication like it's some old-fashioned activity, but it is exactly why younger people use social media. The truth is that most people use social media to gently keep an eye on one another, to see how those they care about are doing without needing to ring them up on the phone every night.

    And this is the last secret of social media: everyone gets to use them in their own way. Newcomers—younger and older—who worry about “getting it right” are thinking that there's a right way to get them. But actually there isn't. Personally, I talk a lot on Microblog. And some people post nothing and they use social media every day as readers. Social media companies would rather see people decorating their networks with pictures and posts, but there's no rule against being a fly on the wall. It's also a fine way to get involved.

    We're quick to forget that the web wasn't invented by 13-year-olds; it was created by today's seniors. I'd never try forcing those with no interest in social networks to use Microblog. But don't let the talk of age divides put you off. There's nothing to stop the older generation from joining in the network their own generation created.

C

    There's a new frontier in 3D printing that's beginning to come into focus: food. Recent development has made possible machines that print, cook, and serve foods on a mass scale. And the industry isn't stopping there.

Food production

    With a 3D printer, a cook can print complicated chocolate sculptures and beautiful pieces for decoration on a wedding cake. Not everybody can do that — it takes years of experience, but a printer makes it easy. A restaurant in Spain uses a Foodini to "re-create forms and pieces" of food that are "exactly the same," freeing cooks to complete other tasks. In another restaurant, all of the dishes and desserts it serves are 3D-printed, rather than farm to table.

Sustainability(可持续性）

    The global population is expected to grow to 9.6 billion by 2050, and some analysts estimate that food production will need to be raised by 50 percent to maintain current levels. Sustainability is becoming a necessity. 3D food printing could probably contribute to the solution. Some experts believe printers could use hydrocolloids (水解胶体) from plentiful renewables like algae(藻类) and grass to replace the familiar ingredients(烹饪原料). 3D printing can reduce fuel use and emissions. Grocery stores of the future might stock "food" that lasts years on end, freeing up shelf space and reducing transportation and storage requirements.

Nutrition

    Future 3D food printers could make processed food healthier. Hod Lipson, a professor at Columbia University, said, "Food printing could allow consumers to print food with customized nutritional content, like vitamins. So instead of eating a piece of yesterday's bread from the supermarket, you'd eat something baked just for you on demand."

Challenges

    Despite recent advancements in 3D food printing, the industry has many challenges to overcome. Currently, most ingredients must be changed to a paste(糊状物) before a printer can use them, and the printing process is quite time-consuming, because ingredients interact with each other in very complex ways. On top of that, most of the 3D food printers now are restricted to dry ingredients, because meat and milk products may easily go bad. Some experts are skeptical about 3D food printers, believing they are better suited for fast food restaurants than homes and high-end restaurants.

    In the depths of the French Guianese rainforest, there still remain unusual groups of (土著的）people. Surprisingly, these people live largely by their own Laws and their own social customs. And yet, people in this area are in fact French citizens because it has been a colony of the French Republic since 1946. In theory，they should live by the French law. However, their remote locations mean that the French law is often ignored or unknown, thus making them into an interesting area of “lawlessness” in the world.

    The lives of these people have finally been recorded thanks to the effects of a Frenchman form Paris called Gin. Gin spent five months in early 2015 exploring the most remote comers of thin area, which sits on the edge of the Amazon rainforest, with half its population of only 250,000 living in its capital, Cayenne.

    “I have a special love for the French Guianese people. I have worked there on and off for almost ten years," says Gin. "I've been able to keep firm friendships with them. Thus I have been allowed to gain access to their living environment. I don't see it as a lawless Und. But rather I Me it as an area of freedom."

    “I wanted to show the audience a photographic record touching upon the uncivilized life," continues Gin. “I prefer to work in black and white, which allows me to show different specific worlds more clearly.”

    His black-and-white pictures present a world almost lost in time. These pictures show people seemingly pushed into a world that they were unprepared for. These local citizens now have to balance their traditional self-supporting hunting lifestyle with the lifestyle offered by the modern French Republic, which bring with it not only necessary state welfare, but also alcoholism, betrayal and even suicide.

    Which kind of diamond is better for the environment and the world we live in: a diamond from a traditional mine or one made in a laboratory?

    Some recent reports suggest the answer may not be so clear. At the very least, these reports provide evidence of tensions between two different sectors of the diamond industry.

    Lab -grown diamond companies say they are more ethical and cause less harm to Earth's environment. The traditional diamond sector notes that its businesses help the communities where they operate mines. It says they provide jobs, help build roads and other infrastructure and make investments in conservation.

    Some companies, such as De Beers, work on both sides. De Beers sells natural and man-made diamonds. In the United States, the Federal Trade Commission(FTC) investigates reports of deceptive, or misleading, advertising. In April, the commission sent warning letters to eight lab-grown diamond companies. One of the FTC's concerns was the use of the word 'eco-friendly', and similar terms, to describe diamonds made in a laboratory. The lab-grown process requires very high temperatures and uses a lot of energy. Trucost is a company that estimates the costs of using natural resources. Asked by the Diamond Producers Association to study the issue, Trucost found the carbon intensity of natural diamonds was lower than lab-grown diamonds.

    The Trucost report did note that diamond miners should reduce their effect on the environment by using more renewable energy, such as wind power and sunlight.

    Darwin noted that some human emotional expressions might have started as part of a physiological function: for example, exposing the teeth to bite food. The function, however, took on meaning and became a form of communication which signals anger.

    The same may be true for the animals. Baby monkeys cry for attention. They also cry to signal to an adult that they want to be carried.

    "Chimpanzees do make upset voice when they are being weaned (断奶) by their mothers or have lost their mothers or another individual, " says Anne Pusey, a professor at the University of Minnesota. "They whimper (呜咽) and cry and scream. When we hear these calls, the emotion involved seems obvious. However, they do not weep in the sense of producing tears. "

    The Iowan researchers can cause the same crying sounds by producing large decreases and then increases in blood flow. The blood flow also goes down when baby rats get cold. Thus, they conclude baby rats cry in the same way that we sneeze. Of course the rat baby could be crying because he's cold and wants his mother to know.

    Why does night fall but never break and day break but never fall？Why are people who ride motorcycles called bikers and people who ride bikes called cyclists？In what other language do people drive in a parkway and park in a driveway？In what other language do they call the third hand on the clock the second hand？

    Let's face it: English is a crazy language. There is no egg in an eggplant, neither pine nor apple in a pineapple and no ham in a hamburger. Sweet-meats are candy， while sweetbreads, which aren't sweet, are meat.

    We take English for granted. But when we explore its paradoxes(悖论), we find that quicksand can work slowly, boxing rings are square, public bathrooms have no baths in them.

    And why is it that a writer writes, but fingers don't fing, grocers don't groce, and hammers don't ham？If the plural of tooth is teeth, shouldn't the plural of booth be beeth? One goose, two geese - so one moose, two meese?

    How can a slim chance and a fat chance be the same, while a wise man and a wise guy are opposites? How can overlook and oversee be opposites, while quite a lot and quite a few are alike? How can the weather be hot as hell one day and cold as hell the next？

    English was invented by people, not computers, and it shows the creativity of human beings. That's why, when stars are out, they are visible; but when the lights are out, they are invisible. And why, when I wind up my watch, I start it; but when I wind up this essay, I end it.