Cleaning your plate may not help feed hungry children today, but the timeworn advice of mothers everywhere may help reduce food waste from the farm to the fork, help the environment and make it easier to feed the world's growing population.

    Hard data still being collected, but experts in Chicago said about 30% to 50% of the food produced in the world goes uneaten. The average American throws away 33 pounds of food each month—about $40 worth, which means each person throws away almost 400 pounds of food. The US Department of Agriculture says that 23% of eggs and an even higher percentage of produce ends up in the trash.

"We forget we have all these fresh fruits and vegetables, and at the end of the week we have to throw them away", said Esther Gove, a mother of three young children in South Berwick, Maine. "Now, I don't buy as much fresh produce as I used to."

    But the effect of food waste arrives far beyond the kitchen. Agriculture is the world's largest user of water, a big consumer of energy and major emitter of greenhouse gases during production. Experts say reducing waste is a simple way to cut stress on the environment and can ease pressure on farmers, who will be called on to feed an expected 9 billion people around the world in 2050, compared with nearly 7 billion today.

    No matter how sustainable (可持续的) farming is, if the food's not getting eaten, it's not sustainable and it's not a good use of our resources. In richer nations, fruit and vegetables end up in the trash because they aren't pretty enough to meet companies' standards, have gone bad in a home refrigerator or aren't eaten at a restaurant. In developing countries, much food spoils before it gets to market due to poor roads and lack of refrigeration. High food prices are another reason, since some people can't afford the food that's produced.

    Astronauts on shorter shuttle missions（使命）often work very long days. Tasks are scheduled so tightly that break times are often used to finish the day's work.  This type of schedule is far too demanding for long missions on the International  Space Station（ISS）.  ISS crewmembers usually live in space for at least a quarter of a year. They work five days on and two days off to mimic the normal way they do things on Earth as much as possible . Weekends give the crew valuable.  Weekends give the crew valuable time to rest and do a few hours of  housework.  They can communicate with family and friends by email , internet phone and through Private video conferences.

    While astronauts cannot go to a baseball game or a movie in orbit, there are many familiar activities that they can still enjoy . Before a mission. The family and friends of each ISS crewmember put together a collection of family photos, messages, videos and reading material for

    The astronauts to look at when they will be floating 370 kilometers above the Earth.  During their mission, the crew also receives care packages with CDs, books, magazines, photos and letters . And as from early 2010, the internet became available on the ISS , giving astronauts the chance to do some “web surfing （冲浪）”in  their personal time.  Besides relaxing with these more common entertainments, astronauts can simply enjoy the experience of living in space.

    Many astronauts say that one of the most relaxing things to do in space is to look out the window and stare at the universe and the Earth's vast land mass and oceans.

    For as long as we've known about it, humans have searched for a cure for cancer. Across the world, countless amounts of time and money have been spend on researching a way to stop the terrible disease.

    But now, it seems like the answer could have been inside our own bodies the whole time.

    Recently, the Food and Drug Administration (FDA) in the US, a government agency that's responsible for healthcare, approved a new form of gene therapy that could mean the end of a certain type of cancer.

    The therapy allows scientists to 'train” the immune cells of sick patients to fight leukemia – a blood cancer that mostly affects young people.

    The exciting new treatment works by removing healthy immune cells from the patient, known as T-cells, which are then altered to be able to “hunt down” cancer cells.

    The cells are then put back into the patient, before they begin to get rid of the patient's leukemia over time, similar to how the body fights off other illnesses.

    'this is truly an exciting new day for cancer patients,” Louis J. DeGennaro, president of the Leukemia and Lymphoma Society, said in a news release. Up until now, a drawn-out （持续很久时间的）and painful bone marrow transplant was the only option for many leukemia patients.

    In this procedure, healthy blood cells are taken from a donor and placed into the sick patient, who also has to go through chemotherapy to allow their body to adjust to the new cells.

    But with a recovery rate of around 83 percent–according to a news release published by the FDA–it's hoped that the days of painful trips to the hospital, or even death, are over for leukemia sufferers.

    “We're entering a new frontier in medical innovation with the ability to reprogram a patient's own cells to attack a deadly cancer,” FDA commissioner Scott Gottlieb said in the release.

    “New technologies such as gene and cell therapies hold the potential to transform medicine and... our ability to treat and even cure many intractable（难治的） illnesses.”

    The Silk Road is a name given to the many trade routes that connected Europe and the Mediterranean（地中海）with the Asian world. The route is over 6,500 km long and got its name because the early Chinese traded silk along it. Although silk was the main trading item, there were many other goods that travelled along the Silk Road between Eastern Asia and Europe. In the course of time, medicine, perfumes, spices and livestock（家畜）found their way between continents.

    The Chinese learned to make silk thousands of years ago. For a long time they were the only ones who knew how to make this precious material. Only the emperor, his family and his highest advisers were allowed to wear clothes made of silk. For a long time the Chinese guarded this secret very carefully. The ancient Romans were the first Europeans who became aware of this wonderful material. Trading started, often with Indians as middlemen（中间人）who traded silk with the Chinese in exchange for gold and silver which they got from the Romans.

    Travelling along the route was dangerous. The hot desert, high mountains and sandstorms made traveling a rough business. Most of the goods along the Silk Road were carried by caravans（商队）. Traders sometimes brought goods from one destination on the silk Road to another, from where the goods would be transported by someone else. Over the centuries people settled along the ancient route and many cities emerged. Later on there were fewer hardships to overcome, but by no means was it easy.

    Religion, languages and diseases also spread along the Silk Road. Buddhism, which originated in India, spread to China along this route. European traders probably brought the plague from Asia to Europe along the ancient road.

    In the early Middle Ages, traffic along the route decreased because of the decline of the Roman Empire. Trading along the Silk Road became stronger again between the 13th and 14th centuries, when the Mongols controlled central Asia. During the Age of Exploration the Silk Road lost its importance because new sea routes to Asia were discovered.

    There have been many problems with our schools today, the biggest of which is closely related to our culture. In general, our culture, as represented in the media, gets excited by famous stars, and constantly stresses that it's what you have, not what you are, that counts. Parents are encouraged to be away from even very small children for most of the day. Too many voters go for politicians who would rather cut school funding than to get rid of tax cuts for the wealthy. All contribute greatly to the problems of educating our children.

    Today's teachers have to deal with a culture that is vastly different than in the past. They report that there is, among more children than ever, a lack of motivation, no drive to succeed or even try. The role models that boys view in the media mostly consist of men in comedies and other shows who are rude and often extremely immature; self-centered overpaid athletes; men in movies, television dramas, video games, etc. who are preoccupied with violence and power. As Leonard Sax wrote in "Boys Adrift", "Teenage boys are looking for models of mature adulthood, but we no longer make any collective effort to provide such models." Girls are attacked not only with such annoying images of males, but also with women who are preoccupied with appearance and are extremely materialistic.

    In such a cultural environment, it is more important than ever to have responsible, loving and caring parents who have enough time and motivation to devote to their children and see to it as their duty to model for them and raise them with high standards of honesty and responsibility along with tending to their physical needs. They need to care enough to see that their children are not attacked with the garbage that comes from movie, television and computer screens. In today's culture, they are basically alone in this effort since, unfortunately, so much is working against them.

    Until we, as a culture, face the truth about ourselves — that we are not providing adequately for a great many of our children — the storm will continue to rage over our education system.

Artificial intelligence（Al）has the potential to develop more efficient methods of farming in order to fight global warming. 

 Global warming threatens every aspect of our everyday lives, including crop production. It will reduce the soil moisture（水分）in areas close to the equator according to a study. We are already seeing the negative impact of these changed growing conditions on our crop production. Climate change harms poorer countries that do not have the money to import food. The result is growing food insecurity. However, agriculture is not just affected by global warming—agriculture is part of a vicious（恶性的）cycle in which farming leads to global warming, which in turn destroys agricultural production. The process of clearing land for agriculture results in widespread deforestation（毁林）and contributes to 40 percent of global methane production. Therefore, to deal with climate change, it is necessary to ensure reforestation—but how? What is the path to efficient, environmentally-conscious farming?

This is where AI enters the scene. Farmers use AI for methods such as precision agriculture; they can monitor crop moisture, soil composition, and temperature in growing areas, enabling farmers to increase production by learning how to take care of their crops and determine the ideal amount of water to use. Furthermore, this technology may help reduce deforestation by allowing humans to grow food in urban areas. It could be especially beneficial for countries in Latin America and the Caribbean, where much of the population lives in cities. 

However, AI is far from a silver bullet—it could actually contribute to global warming as well. Due to the large amount of data that AI needs to process, training a single AI releases five times the emissions that an average car would give off during its lifetime. Further, securing access to AI on a global scale may pose some challenges. Countries will need experts in the field who can successfully use the technology and Internet connection, neither of which are always readily available. Therefore, there is still a long way for developing countries to take advantage of the benefits of AI. 

Given these concerns, global leaders must consider the potential costs, and the environmental consequences of data processing before developing AI for use in agriculture.