Every year gray whales swim a 10,000 miles round-trip, from the cold waters near Alaska, down the coast of North America to the warm waters near Mexico, and back again. It is one of the longest migrations (迁徙) of any mammal (哺乳动物).

    All day, all summer long, in the cold waters near Alaska, gray whales eat and eat.

    Instead of teeth, gray whales have baleen (鲸须) they use to get food from ocean water. They get big mouthfuls of muck (淤泥) from the ocean floor, then push that muck right back out through their baleen. The mucky water flows through, but tiny animals get trapped in the baleen and licked up.

    When the water starts to freeze, the whales begin their long trip south. They swim night and day, without stopping to eat or rest. During the long journey, migrating whales may push their heads out of the water to see where they are.

    Two months later, the whales reach Mexico. Babies are born here in warm, shallow (浅的) waters called lagoons (濒海湖). Ocean lagoons have no food for the adults, but the babies are safer here than in the open seas. All winter the babies grow big and strong.

    In spring first the dads and teenagers leave the lagoons, then the moms with babies. Migrating gray whales swim close to shore, especially moms with babies. The ice is melting up (融化) north, and it's time for the hungry whales to make the long journey back to their summer feeding grounds.

    Asia can boast(吹嘘) that it has some of the best beaches in the world. Sihanoukville, Cambodia is a seaside town located 200km or a four­hour bus ride away from the country's capital, Phnom Penh. With several beaches and small offshore islands, it is definitely not a place to miss out if you are intending to visit Angkor Wat, as the beaches there are stunning and still unspoiled by mass tourism.

    Serendipity Beach

    Serendipity Beach is the most popular beach for the masses, since it is the most accessible beach, being the nearest one from the main town area. There are plenty of bars scattered around the beach, so be prepared for the crazy parties every night.

    Ochheuteal Beach

    Ochheuteal Beach is located south of Serendipity Beach, and it's a bit of an improvement from Serendipity Beach itself in terms of the people that go there. Over here, there are bars and pubs, but at night, don't expect wild parties like at the Serendipity Beach area.

    Otres Beach

    All the way down south, near Moat Peam, lies a hidden gem called Otres Beach. This is where you can get your yoga suit on and practice meditation(冥想). This is the quietest beach in Sihanoukville and it is the least crowded, with very few parties. If your idea of a beach holiday is just yourself and the sun, sea and sand, this place is for you.

    Koh Rong

    Koh Rong is an island off Sihanoukville that is covered with beautiful sandy beaches. True relaxation lies at Long Beach, which is located on the other side of the island. Clear water surrounds the beach, and once you get there, you'll be greeted with fine white sand.

    Koh Rong doesn't have any roads, so there are no cars or motorbike rentals — everything is mostly on foot.

    A recent experiment proves that bees can save time and energy when they fly around to different flowers.

    Dr Nigel Raine, from the Royal Holloway University of London, has always been interested in finding out why animal behave like they do. He is also interested in bees. It was not a surprise when he and some other scientists from Queen Mary University of London discovered that bees can quickly solve a problem that takes computers many days.

    Flowers make pollen (花粉), and when bees visit them, they carry the pollen to other flowers. The plants need the pollen to make seeds that will grow. Dr Raine notes that we get a lot of our food from plants, so it is important to know how the bees move around and take the pollen between flowers. The scientists wanted to examine the journey that the bees take and how they save energy when they do this. They completed the experiment on the roof of Queen Mary University, using artificial flowers and a large amount of nectar, a sweet liquid produced by flowers. They taught one bee to visit all the flowers in one place at the same time. When the bee got to know the location of the flowers well, they saw how it flew around and returned home with the nectar. After this, they changed the locations of the flowers. The scientists thought the bee would follow the route it knew already. This would mean that it followed a longer route than it needed to, and so it would use more energy. They watched the bee carefully as it travelled between the flowers in their new location, and they made notes. But in the experiment, the bee changed its route and flew a shorter distance.

    The problem that the bee solved is similar to a maths puzzle called the 'travelling salesman problem'. A salesman who goes to different places to sell things wants to travel the shortest distance. But he has to calculate the length of many possible routes to know which one is the shortest. A computer can calculate this but the experiment shows bees can do the same calculation quickly with a tiny brain. Scientists are very interested in how they do this. It would help us to understand how pollen is moved around. In addition, if they find this out, it could help us to improve communication networks. This might help humans to reduce traffic jams when there is an accident, for example.

    Have you ever been to London? Here is some hotel information for you.

    Recently, American President Trump announced his budget. One of the budgets would cut all money to the Institute of Museum and Library services and libraries across the United States. However, as far as I'm concerned, we need to save our libraries.

    Libraries provide books and after-school programs for children. They encourage literacy (识字）with summer programs. They help inspire a life-time love of learning and reading in children of all ages. Without them, where will kids with no Internet at home do their homework? Where will kids have a place to study or borrow books after school? Therefore, we need libraries for our kids. We need them so that kids can grow up with a place, other than school , where learning and exploration is encouraged. For adults, libraries serve as a place where they can use the Internet to apply for jobs, get job training, early voting centers as well as book clubs to help make new friends. It can also serve as a place to pick up a book and learn something new. What's more, they can also borrow a book and get away from it all.

    Libraries save our information for the next generation. When we live in an age of alternative (选择性的）facts, where science is ignored in favor of personal feelings, we need libraries now more than ever. We need them to educate ourselves on the facts and hold the government responsible for them. We need them to have strong public participation.

    If you agree with me, you shouldn't be silent on this issue. You can write or call directly to tell the president to save our libraries. You can also write to both your state Senators (参议员）and your district representative. If you do not know who they are, you can find out here. Let them know this is a beneficial issue because all people use public libraries in their daily life.

At Englands University of Plymouth, Professor Eduardo Miranda has been programming pairs of robots to compose music. Miranda's robots have simple " vocal cords" (声带)and are programmed to sing and to listen to each other. The robots' unique warbling sounds (颤音) do not perfectly match the human voice, but each machine is exactly sharing music with the other in a new and unique way.

Each robot is equipped with speakers, software that mimics the human voice, a mouth that opens as it "sings," a microphone for ears, and a camera for eyes. The robots also move. Miranda hopes that by studying his robot vocalists, he can discover something about how and why humans create, perform, and listen to music.

When the robots sing, first one robot makes six random sounds. Its partner responds with more sounds. The first robot analyzes the sounds to see if their sequences (序列)) are similar. If they are, it nods its head and commits the sounds to memory, and the second robot notices and "memorizes" the musical sequence, too. If the first robot thinks the sounds are too different, it shakes its head and both robots ignore the sounds. Then the process continues.

Miranda set up an experiment in which he left the two robots alone in his study for two weeks. When he returned, his little warblers had, by imitating each other, not only shared notes but combined them. The product of their cooperation was far from symphonic, but the robots had begun to combine the notes into their own self-developed "songs".

With the help of his warbling robots, one of Miranda's goals is to create music that no human would ever compose. Miranda believes the robots are ideal for this purpose because they would not be influenced by any existing musical styles or rules.