What will power your house in the future？Nuclear, wind, or solar power？According toscientists at the Massachusetts Institute of Technology(MIT)in the US, it might beleaves—but artificial(人造的)ones.

    Natural leaves are able to change sunlight and water intoenergy. It is known as photosynthesis(光合作用). Nowresearchers have found a way to imitate this seemingly simple process.

    The artificial leaf developed by Daniel Nocera and hiscolleagues at MIT can be seen as a special silicon chip with catalysts(催化剂). Similar tonatural leaves, it can splitwater into hydrogen and oxygen when put into a bucket of water. The hydrogenand oxygen gases are then stored in a fuel cell, which usesthose two materials to produce electricity, located eitheron top of a house or beside the house.

Though the leaf is only about the shape of a poker card, scientistsclaimed that it is promising to be an inexpensive source of electricity indeveloping countries.“ One can imagine villages in India and Africa not longfrom now purchasing an affordable basic power system based on this technology, ”said Noceraat a conference of the American Chemical Society.

    The artificial leaf is not a new idea. The first artificial leafwas invented in 1997 but was too expensive and unstable for practical use. Thenew leaf, by contrast, is made ofcheap materials, easy to useand highly stable. In laboratory studies, Nocera showedthat an artificial leaf prototype(原型)could operatecontinuously for at least 45 hours without a drop in activity.

    The wonderful improvements come from Nocera's recent discoveryof several powerful, new andinexpensive catalysts. These catalysts make the energy transformation insidethe leaf more efficient with water and sunlight. Right now, the new leafis about 10 times more efficient at carrying out photosynthesis than a naturalone. Besides, the device canrun in whatever water is available；that is, it doesn'tneed pure water. This is important for some countries that don't have access topure water.

    With the goal to “make each home its own power station” and“give energy to the poor”, scientistsbelieve that the new technology could be widely used in developing countries, especially inIndia and rural China.

    A layover (临时滞留) or flight delay can be extremely fun in these international airports.

Munich Airport, Germany

    Aviation (航空) lovers passing through Munich can take a behind－the－scenes tour to learn how the airport operates. Visitors can also tour three historic aircraft and a retired rescue helicopter, climb up to a 28－metre high observation platform for an up－close view of take－offs and landings, and watch films on aviation in the airport's 60－seat cinema. Travelers can also kill layover time at an 18－hole mini－golf course, or even stop in for a teeth cleaning at the airport dental office.

Changi Airport, Singapore

    After a long flight to Singapore, travelers can relax in a Balinese－style swimming pool, work out at the airport gym, or enjoy a drink and live musical performances at the airport's Music Bar. The airport also boasts a tranquil butterfly garden, and a “fragrant garden” which is home to 15 species of plants and trees. Free movies at one of two airport cinemas also keep passengers entertained.

    Schiphol Amsterdam Airport, the Netherlands

    Schiphol is Europe's fifth－largest airport. Here passengers can view the works of Dutch masters free of charge, and try their luck at airport's casino (赌场). You can even have your wedding ceremony at Schiphol—couples can choose from four different wedding packages, including a 1930－style ceremony held on a Dakota military aircraft.

    San Francisco International Airport, California

    The airport's 24－hour AirTrain not only moves passengers between terminal, but also provides a fun view of the runways. There are three aquariums (水族馆) to explore, along with interactive play areas, an aviation museum, and a library. If that's not enough to keep the little ones busy, travelers can rent portable DVD players and movies for use in the airport.

    5000 B.C.— People began to farm along the Nile River in Egypt.

    2950B.C. — Egypt was first united under MENES.

    2600B.C. — The first pyramid of Egypt, the Pyramid of Djoser, was built.

    2500 B.C. — The great Pyramid of Gina was built.

    2000 B.C. — The Bantu Peoples began to migrate into central and southern Africa.

    1279 B.C. — Rameses II became pharaoh（法老）of Egypt.

    1070 B.C. — The kingdom of Kush gained its independence from Egypt.

    814 B.C. — The city of Carthage was established by the Phoenician Empire.

    715 B.C. — Kush conquered Egypt and ruled it until 662 B.C.

    650 B.C. — Cathage became independent. It grew into one of the most powerful cities on the Mediterranean Sea.

    590 B.C. — The capital of Kush was moved from Napata to Meroe.

    525 B.C. — The Persians conquered Egypt.

    332 B.C. — The Greeks led by Alexander the Great conquered Egypt.

    264 B.C. — Carthage fought in the First Punic War.

    146 B.C. —Cathage was defeated by Rome. Roman forces destroyed the city.

    30 B.C. — Cleopatra VII, the last pharaoh of Egypt, died. Egypt became part of Rome.

    In early February 2019, 51-year-old Rainer Schimpf and his team set out to film South Africa's Sardine Run off the coast of Point Elizabeth Sardine Run, the annual migration(迁徙)of billions of sardines (a small sea fish), is a big draw for large predators, especially the dolphin and whale. Predators are animals that kill and eat other animals. In an attempt to obtain the best images of the incredible natural phenomenon, Rainer dived into the middle of a spinning ball of fish. Suddenly the sea moved around violently, and the experienced diver and his photographer Heinz Toperczer, who was filming from the boat, instantly realized something strange was going on. Suddenly dolphins shot out of the water, a white spray came out and then a whale appeared and grasped Rainer

    While Toperczer was filming the terrifying turn of events with his video camera, Rainer, who was trapped had first and engulfed(吞噬)in darkness inside the whales mouth, was trying to survive. Nothing can actually prepare you for the event when you end up inside the pure instinct(本能), "the diver told Barcroft TV. "Knowing in the whale's mouth, I tried to control my fear. But I was convinced that it was going to dive down and release me much deeper in the ocean."

    "The whale quickly realized he was no sardine! As the whale turned sideways, he opened his mouth slightly to release me, and I was washed out, together with what felt like tons of water, of his mouth," recalled Rainer. Though the entire incident lasted just 1.8 seconds, it felt like a year to Rainer.

    Still holding his underwater camera in his hand, the diver swam to his boat, where he was quickly rescued by the members of the team. The terrible adventure did not disturb Rainer for too long. After checking to ensure he had no injuries, the diver returned to the water to seek out more.

    I came to the United States ten years ago. I would always say that I was trying to study, but there were always things like work and my kids that would not allow me to start.

    Now I realized that those were only excuses. What stopped me was that I was afraid to start studying again. I always believed I would learn by myself.

    One day, however, my son told me that he was sad because his friends would come over and I didn't understand them because I didn't speak English. He was also sad because I could never help him with his homework. That same day, I told myself, "Rocio, you have to start believing in yourself and you will see you can make it."

    The next day, I went downtown to look for a big banner (横幅) in front of the school which said that they offered classes for adults. I came in to see if I could join, but the classes were closed already. That night I took the kids to the movies, and on the way back, I told them we would take a new route. I ended up getting lost. That's the way I found Chaffey College. The following Monday, I went to ask for information. They told me that summer school was starting that week.

    That's how I started studying English last summer. It is difficult, but I have had great rewards. My daughter had written a story for school. It was about the female they most admired and why. She wrote that I was the person she most admired because I had started going to college. I will never forget this.

    A study examining the children of people evacuated(撤离) during the WWII showed the daughters of female evacuees were up to four times more likely to suffer from serious mental health conditions compared to those whose parents stayed at home.

    In the largest enquiry ever of its kind, researchers examined the health records of 3000 children of Finnish people evacuated to Sweden during the 1941-1945 conflict with Soviet Russia. The evacuees, many of whom were at a pre-school age, were placed with foster families in Sweden and were forced to learn Swedish, later returning to Finland. The study found that the female children of these girls had an increased risk of being hospitalized for conditions such as depression. However, this was not the case with children of boys evacuated during the war.

    The study could not determine why. One possibility is that the stress of the evacuees' experience affected their psychological development in ways that influenced their parenting style. Another possibility is that the evacuees' experience resulted in epigenetic changes—changed in the way genes are expressed. For example, the researchers mentioned an earlier finding that Holocaust survivors have higher levels of methyl groups bound to the FKBP5 gene and have passed his change on to their children. This higher level of methyl groups appears to change the production of cortisol, a hormone(荷尔蒙) that controls the stress response.

    "The Finnish evacuation was intended to protect children from the harm associated with the country's wars with the Soviet Union", said study co-author Dr Torsten Santavirta, from Uppsala University.

    "Our observation of the long-term psychiatric(精神病的) risk that reached into the next generation is concerning and stresses the need to weigh benefits as well as potential risks when designing policies for child protection".