Food serves as a form of communication in two basic ways. Sharing bread or other foods is a common human tradition that can promote unity and trust. Food can also have a special meaning, and play an important role in a family or culture's celebrations or traditions. The foods we eat—and when and how we eat them—are often unique to a particular culture or may even differ between rural(郊区的) and urban(市区的) areas within one country.

    Sharing bread, whether during a special occasion(时刻) or at the family dinner table, is a common symbol of togetherness. Many cultures also celebrate birthdays and marriages with cakes that are cut and shared among the guests. Early forms of cake were simply a kind of bread, so this tradition has its roots in the custom of sharing bread.

    Food also plays an important role in many New Year celebrations. In the southern United States, pieces of corn bread stand for blocks of gold for prosperity(兴旺) in the New Year. In Greece, people share a special cake called vasilopita. A coin is put into the cake, which signifies(预示) success in the New Year for the person who receives it.

    Many cultures have ceremonies to celebrate the birth of a child, and food can play a significant role. In China, when a baby is one month old, families name and welcome their child in a celebration that includes giving red-colored eggs to guests. In many cultures, round foods such as grapes, bread, and moon cakes are eaten at welcome celebrations to represent family unity.

    Nutrition(营养) is necessary for life, so it is not surprising that food is such an important part of different cultures around the world.

    In 1917 Orville Wright predicted that “the aeroplane will help peace in many ways —in particular I think it will have a tendency to make war impossible.” Earlier in 1904, American journalist John Walker declared, “As a peace machine, the value of the aeroplane to the world will be beyond computation.” This wasn't the first grand promise of technology. In that same year Jules Verne announced, “The submarine(潜艇) may be the cause of bringing battle to a stoppage.”

    Alfred Nobel, sincerely believe his dynamite(火药) would be a war obstacle: “My dynamite will sooner lead to peace than a thousand world conventions(公约).” Similarly, when Hiran Maxim, inventor of the machine gun, was asked in 1893, “Will this gun not make war more terrible?” he answered, “No, it will make war impossible.” Gugliemo Mareconi, inventor of the radio, told the world in 1912. “The coming of the wireless time will make war impossible, because it will make war ridiculous.” General James Harbord, chairman of the board of RCA in 1925, believed, “Radio will serve to make the concept of Peace on Earth, Good Will Toward Men a reality.”

    David Nye, a historian of technology, adds to the list of inventions imagined as abolishing war forever and leading to universal peace the hot-air balloon, poison gas, land mines and laser guns.

    It is not that all these inventions are without benefits—even benefits toward democracy（民主）. Rather, it's the case that each new technology creates more problems than it solves. “Problems are the answers to solutions,” says Brian Arthur.

    Most of the new problems in the world are problems created by previous technology. These problems are nearly invisible to us. Every year 1.2 million people die in automobile accidents. The technological transportation system kills more people than cancer. Global warming, environmental poisons, nuclear terrorism, and species loss, are only a few of the many other serious problems troubling people.

    If we embrace(拥抱) technology we need to face its costs.

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    A new report shows that there are just 7,100 cheetahs now left in the wild. Cheetahs are in trouble now.

    According to the study, more than half of the world's surviving cheetahs live in one zone that covers six countries in southern Africa. Cheetahs in Asia have nearly died out. It's thought that only fewer than 50 cheetahs live in Iran.

    The cheetah runs across lands far outside protected areas. Some 77% of their habitat falls outside these protected areas. As a result, the cheetah struggles because these lands are increasingly being developed by farmers and the cheetah's food is decreasing because of human hunting.

    In Zimbabwe, the cheetah population has fallen from around 1,200 to just 170 in 16 years, with the main cause being major changes in land ownership.

    Researchers say that the threats cheetahs are facing have gone unnoticed for far too long. “Given the nature of the cheetah, it has been difficult to gather information on them,” said Dr Sarah Durant, the report's lead author. “Our findings show that the large space requirements for cheetahs and various threats faced by them in the wild mean that they are likely to be in danger of dying out.”

    Another big concern about cheetahs has been the illegal trafficking (非法交易) of young cheetahs. The young cats can fetch up to $10,000 on the black market. Some 1,200 young cheetahs are known to have been trafficked out of Africa over the past 10 years but around 85% of them died during the journey.

    If the cheetahs are to survive, then immediate efforts must be made.

    July is a month of fun-filled activities for kids and teens as long as you know where to find them. When you want some fun activities for July, consider these ideas happening in this month.

    When I was a boy there were no smart phones. Computers were something you saw on STAR TREK(星际航行), and our television only got one channel clearly. Still, I was never bored. The fields, hills, and woodlands around my house were the nature ready-made playgrounds.

    I can remember once hiking to a nearby lake and slowly walking around it. At the backside of it I was amazed to find an old, one-lane, dirt road that I had never seen before. I immediately set out to travel it. It was full of holes and muddy tracks and deep woods bordered it on both sides, but exploring it still seemed like a fine adventure.

    I walked on and on for what seemed like hours. I was sure my guardian angel was whispering in my ear to turn around and head back home but I was stubborn and even a bit stupid, so I walked on.

    The dirt road give way to a rock one and then a paved one, yet there was still neither a car nor a house in sight. My legs were getting tired. I noticed that the sun was starting to go down and I grew scared. I didn't want to end up trapped on this road in the dark of night, but I was sure it would be dark before I could make my way back to the lake again.

    I was almost in tears when I turned one last curve(弯曲处) and saw something in the distance. It was a house that I recognized. My heart leapt up! I jumped up and down and laughed out loud. I knew the way home! It was still over a mile away but my legs felt like feathers and I hurried back to my house in no time. I walked in with a big smile on my face just in time for dinner.

    I remembered this recently when I saw a sign that said, “All roads lead Home.” This is true. In this life all roads no matter what their twists(弯曲) and turns are can lead us home again. They can lead us to our homes here on Earth. They can lead us to our homes in our heart, if we can insist.

    What do you remember about your life before you were three? Few people can remember anything that happened to them in their early years. Adults' memories of the next few years also tend to be unclear. Most people remember only a few events—usually ones that were meaningful and distinctive, such as being hospitalized or the birth of a new baby.

    How might this inability to recall early experiences be explained? The passage of time does not account for it; adults have excellent recognition of pictures of people who attended high school with them 35 years earlier. Another seemingly reasonable explanation—that infants do not form enduring memories at this point in development—also is incorrect. Children two and a half to three years old remember experiences that occurred in their first year, and eleven month olds remember some events a year later.

    However, three other explanations seem more promising. One involves physiological changes relevant to memory. Maturation of the frontal lobes (额叶) of the brain continues throughout early childhood, and this part of the brain may be critical for remembering particular episodes in ways that can be recalled later. Demonstrations of infants' and very young children's long-term memory have involved their repeating motor activities that they had seen or done earlier, such as reaching in the dark for objects, putting a bottle in a doll's mouth, or pulling apart two pieces of a toy. The brain's level of physiological maturation may support these types of memories, but not ones depending on clear verbal descriptions.

    A second explanation involves the influence of the social world on children's language use. Hearing and telling stories about events may help children store information in ways that will endure into later childhood and adulthood. Through hearing stories with a clear beginning, middle, and ending children may learn to take out the idea of events in ways that they will be able to describe many years later. Consistent with this view parents and children increasingly engage in discussions of past events when children are about three years old. However, hearing such stories is not sufficient for younger children to form enduring memories. Telling such stories to two year olds does not seem to produce long-lasting verbalizable memories.

    A third likely explanation for infantile memory loss involves mismatch between the ways in which infants encode information and the ways in which older children and adults recall it. Whether people can remember an event depends critically on the fit between the way in which they earlier encoded the information and the way in which they later attempt to recall it. The better the person is able to reconstruct the perspective from which the material was encoded, the more likely that recall will be successful.