As a Chinese saying goes, "Taste is actually a memory of childhood". Local specialty food may not be popular among all people, but it offers outsiders a glimpse of local culture and history.

    Gongcheng "oil tea" is such a kind of food that would be considered "weird" by many first-time visitors to the remote county in the north of the Guangxi Zhuang Autonomous Region. Many people dislike its bitter and astringent(涩的) flavor when they take a sip.

    "It felt like drinking Chinese herbal medicine. I never expected that I would gradually accept it afterwards, and even become addicted to it," said a traveler surnamed Zhang who comes from Shijiazhuang in northern China's Hebei province.

    Langshan village is said to be the birthplace of Gongcheng "oil tea" whose ideal ingredients are green tea and fermented tea. The village has preserved well its buildings and roads dating back to late Qing Dynasty (1644-1911), as well as its traditional way of making the special tea.

    Lin Fengyou, 60, introduced the cooking process. She looks younger than her age, and attributes this to the benefits of drinking "oil tea" throughout the year.

    The first procedure is to use a wooden hammer to pound the tea while heating it in an iron pot, and then add edible oil and boiled water afterwards. She filters off the solid residues(余渣), and pours the glue-like green tea soup into bowls. Then, she adds salt, caraway seed, green onion, dried rice, fried groundnuts, sliced taro and fried beans.

    The taste of the "oil tea" is a mixture of the distinctive flavors of all its ingredients. Local people usually eat it together with glutinous rice(糯米) balls, rice dumplings and glutinous rice cake.

    The villagers consume "oil tea" three times a day. The tea soup is a healthy and refreshing food. "The tea soup to us is coffee to Westerners", said Lin. "But it is tastier."

    Salt plays an important role in our daily diet. Even a small reduction(减少) in salt in the diet can be a big help to the heart. A new study used a computer model to predict -how just three grams less a day would affect heart disease in the United States.

    The result: Thirteen percent fewer heart attacks. Eight percent fewer strokes（中风）. Four percent fewer deaths. Eleven percent fewer new cases of heart disease. And two hundred forty billion dollars in health care savings. Researchers found it could prevent one hundred thousand heart attacks and ninety-two thousand deaths every year．

    The study is in the New England Journal of Medicine. Kirsten Bibbins-Domingo at the University of California San Francisco was the lead author. She says people would not even notice a difference in taste with three grams, or one-half teaspoon, less salt per day. The team also included researchers at Stanford and Columbia University.

    Each gram of salt contains four hundred milligrams of sodiu(钠), which is how foods may list their salt content．

    The government says the average American man eats ten grams of salt a day. The American Heart Association advises no more than three grams for healthy people. It says salt in the American diet has increased fifty percent since the nineteen seventies, while blood pressures have also risen. Less salt can mean a lower blood pressure.

    New York City Mayor Michael Bloomberg is leading an effort called the National Salt Reduction Initiative. The idea is to put pressure on food companies and restaurants. Critics call it government interference(干预).

    Mayor Bloomberg has already succeeded in other areas, like requiring fast food places in the city to list calorie information. Now a study by the Seattle Children's Research Institute shows that the calorie information on the menu can influence what parents order for their children. Ninety-nine parents of three to six year olds took part. Half had calories between the two groups for foods that the parents would have chosen for themselves. McDonald's menus clearly showing how many calories were in each food. Parents given the counts chose an average of one hundred two fewer calories when asked what they would order for their children. Yet there was no difference in calories between the two groups for foods that the parents would have chosen for themselves.

    Study leader Pooja Tandon says even small calorie reductions on a regular basis can prevent weight gain over time. The study was published in the journal Pediatrics.

    Food festivals around the world

    In our everyday lives we meet situations in which we take many things for granted（不去重视）.We only treasure things when they are gone.This is a sad truth of human nature.One day,I found myself as a witness to a similar situation.

    One evening,I left work and boarded the train.After entering,I noticed something unusual.The center of the car had a few empty seats while both ends were crowded with people standing.I didn't pay much attention and sat down on one of the empty seats.I sensed a funny smell.It wasn't long before I noticed a homeless person sleeping on three seats in front of me.He was bleeding from his nose.Why wasn't anyone helping him?

    His clothes were torn and he was giving off a strange smell.Along with the smell,his eyes were dull,watery and red.Occasionally he scratched himself and people looked at him as if he had committed a crime.As the train stopped at stations and more people came in they covered their noses and faced away from him.All the seats around him were empty.

    Suddenly,he began to swear at the people around him.A plain clothes policeman who looked like a construction worker took out his certificate and showed it to the homeless man.The officer,not wanting to touch the homeless man, told him his rights and directed him to exit the train.As the officer walked the man out of the train,the homeless man turned around and said "MY HOME!" and started crying.

    A man doesn't value things until they are gone.If he didn't have a home,at least he had freedom.Now he has neither.No one wants to help someone who won't help himself.

For future humans to survive long periods on Mars, growing food on the planet is a must. It would be too costly and risky to rely upon rocket deliveries to meet the food needs of settlers. With this in mind, scientists are exploring ways to improve space farming.

Researchers work in a controlled greenhouse. They have identified a way that could improve crop production in simulated （模拟的） Martian soil, with different crops grown together. The method is called "intercropping", invented by ancient Maya farmers in what is now Central America.

In their experiments, the researchers grew cherry tomatoes, peas and carrots together in small, round containers. Tomatoes grown in this way produced about double the amount of tomatoes grown alone—or "monocropped"—in the same simulated Martian soil. The tomatoes were also bigger. They flowered and matured earlier, gave more fruit per plant and had thicker stems. The amounts of peas and carrots did not increase with intercropping.

Rebeca Goncalves, an astrobiologist and lead writer of the study, said the research is the first time the intercropping technique was used in space soil, and that it was a big find—one that they could now build further research on. The crops were grown in simulated Martian regolith, a soil with no organic matter —a near-perfect physical and chemical match to real Martian soil.

The researchers added useful bacteria and nutrients. They also controlled the gases, temperature and humidity inside the greenhouse to match conditions expected in a Martian greenhouse. Intercropping involves growing plants with properties that could help each other grow. The method makes the best use of resources including water and nutrients.

The researchers said the tomato plants in intercropping may have benefited from being close to the pea plants. That is because the peas are good at turning nitrogen from the air, with the help of bacteria introduced into the soil, into an important nutrient. Overall, the tomatoes, peas and carrots grew well, though not as well as in Earth soil in the same greenhouse.

Tea is currently the world's most popular drink, only after water. However, there was a time when tea was known only to the Chinese. So, how did tea originate in China? And how did it get to conquer the world to the extent that people often describe something they really like as their "cup of tea"? 

While we know that tea drink started in China, its true origin remains something unknown. Legend has it that about 5, 000 years ago, Shennong came across tea when dried leaves blew into a pot of boiling water. Following his discovery, tea was used as medicine, included in meals and later offered as a refreshing drink to officials and noblemen. Eventually, it became a common drink enjoyed by all Chinese people. 

The love of tea inspired many people to write about it. Over the years, tea drinking became an important part of China's rich culture. The great poet Du Fu described his tea-drinking experience in poetic language. Lu Yu, a tea master, wrote The Classic of Tea, which remains the earliest and most famous detailed study on tea in the world. 

It is then not surprising that the beauty of tea was eventually spread to a wider world. Tang and Song Dynasties needed strong Tibetan horses, so the Tea Horse Road was born. Porters (脚夫) carrying back-breaking loads of tea bricks made their way through dangerous snow-covered mountain passes, to trade Sichuan and Yunnan tea for horses. Over time, the gift of tea was further delivered to Western Asia and Easten Africa. As early as the Tang Dynasty, Saicho, a Japanese monk came to study in China and took tea seeds and tea-making customs to Japan. Around the 1600s, tea was shipped to Europe from China by Portuguese and Dutch sea traders.