Honey from the African forest is not only a kind of natural sugar, it is also delicious. Most people, and many animals, like eating it. However, the only way for them to get that honey is to find a wild bees' nest and take the honey from it. Often, these nests are high up in trees, and it is difficult to find them. In parts of Africa, though, people and animals looking for honey have a strange and unexpected helper—a little bird called a honey guide.

    The honey guide does not actually like honey, but it does like the wax(蜂蜡) in the beehives(蜂房). The little bird cannot reach this wax, which is deep inside the bees' nest. So, when it finds a suitable nest, it looks for someone to help it. The honey guide gives a loud cry that attracts the attention of both passing animals and people. Once it has their attention, it flies through the forest, waiting from time to time for the curious animal or person as it leads them to the nest. When they finally arrive at the nest, the follower reaches in to get at the delicious honey as the bird patiently waits and watches. Some of the honey, and the wax, always falls to the ground, and this is when the honey guide takes its share.

    Scientists do not know why the honey guide likes eating the wax, but it is very determined in its efforts to get it. The birds seem to be able to smell wax from a long distance away. They will quickly arrive whenever a beekeeper is taking honey from his beehives, and will even enter churches when beeswax candles are being lit.

    Scientists in Argentina have created the world's first cow with two human genes that will enable it to produce human-like milk.

    Genetic engineering was used to introduce the "mothers'milk" genes into the animal before birth, according to the National Institute of Agribusiness Technology in Buenos Aires.

    As an adult, the cloned cow "will produce milk that is similar to that of humans", which will prove "a development of great importance for the nutrition of infants(婴儿)", said the institute. "The cloned cow, named Rosita ISA, is the first in the world with two human genes that contain the proteins present in human milk," said the statement.

    In April, scientists in China published details of research showing that they had created dairy cows which produced milk containing proteins found in human breast milk. But the Argentine team said the Chinese only introduced one human gene, while their research involved two,  meaning the milk will more closely resemble that of humans.

    “Our goal was to raise the nutrition value of cows'milk by adding two human genes, which do good to the immune system of infants,” said Adrian Mutto, from the National University of San Martin which worked with the institute.

    Cristina Kirchner, President of Argentina, said that the scientific institute made all Argentines proud. She also said that she had rejected the "honor" of having the cow named after her. "They came to tell me that the name is Cristina, but what woman would like to have a cow named after her? It appeared to me to be more proper to call it Rosita.”

    In China, many people are leaving the countryside to find jobs in the cities, because the countryside is much poorer than the city, and often there isn't much work there. Services such as hospital and transport are usually much better in the city than in the countryside. They hope that their lives will improve when they move to the city.

    But in the big cities of Europe like London or Pads, people are moving out of the city. These rich families want to live a quieter life. They are tired of the noise and the dirt of the city, and they are tired of the crowded streets, crowded trains and buses. They don't want to live in the cities any more. They want a house with a garden in the countryside, and breathe the fresh air there.

    So they move out of the cities. Some don't go very far, just a little way out of the city, to the towns near the cities, other people move to the real countryside with sheep, cows and green fields. There, they start new lives and try to make new friends.

    Not all those who move from the city to the countryside are happy. After two or three years, many people who have done this feel that it was a big mistake. They don't make so much money and there isn't much work to do. People in the countryside are very different and aren't always very friendly.

    As a result, quite a lot of people who have moved to the countryside move back to the city. "

    It's wonderful to see crowds in the streets and cinema lights," they say.

    Nations in the UN have agreed that the world needs to completely stop plastic waste from entering the oceans. The UN resolution(决议) has no timetable. But ministers at an environment summit believe it will set the course for much tougher policies and send a clear signal to business.

    Under the resolution, governments would establish an international task force(特遣小组) to advise on fighting what the UN's oceans chief has described as a world crisis. One controversial issue is the wish to include businesses on the global task force. Ministers say the problem will not be solved without business, but green groups point out that some firms in the plastics industry have been against restrictions for decades. Vidar Helgesen, a leading voice in the talks, told BBC News, “Business is listening to markets and seeing how marine litter(海洋垃圾) is a growing popular concern. It's possibly the fastest－growing environmental problem and it's therefore a fast－growing problem for business. We need to bring on board those companies that want to change things, and then look at taxes and regulations to make more companies act.”

    Certainly, there has been resistance from plastics firms to the bans. One UN delegate, who did not want to be named, stated that journalists in some countries were being paid by the plastics industry to write stories about job losses following the plastic bag ban. But they did not mention the jobs being created in alternatives, such as labour－intensive basketwork, which provides work for the rural poor. But some governments are standing firm, and the meeting has witnessed individual nations declaring tougher action against single－use plastic bags.

    The UN's spokesman Sam Barratt told BBC News, “Of course we would have liked to have gone further, but this meeting's made real progress. There's now a sense of urgency and energy behind the issue that we haven't quite seen before. What is obvious, though, is that the UN can't solve this problem on its own. We need to do it in partnership with governments, businesses and even individuals.”

    Shark attacks not only disturb beach activities, but can affect associated tourist industries. Shark nets are a common solution to preventing shark attacks on beaches, but they cause dangers to sea ecosystems.

    Seeking a cost-effective way to monitor beach safety over large areas, we have developed a system called Shark Spotter. It combines artificial intelligence (AI), computing power, and drone (无人机) technology to identify and warn lifesavers to sharks near swimmers. The project is a cooperation between the University of Technology Sydney and The Ripper Group, which is pioneering the use of drones—called "Westpac Little Ripper Lifesavers"—in the search and rescue movement in Australia.

    SharkSpotter can detect sharks and other potential threats using real-time aerial imagery. The system analyses video from a camera attached to a drone to monitor beaches for sharks, send warnings, and conduct rescues. Developed with techniques known as "deep learning", the Shark Spotter system receives imagery from the drone camera and attempts to identify all objects in the scene. Once certain objects are detected, they are put into one of 16 categories: shark, whale, dolphin, rays, different types of boats, surfers, and swimmers.

    If a shark is detected, Shark Spotter provides both a visual sign on the computer screen and an audible warning to the operator. The operator confirms the warning and sends text messages from the Shark Spotter system to the Surf Life Savers for further action. In an emergency, the drone is equipped with a lifesaving flotation pod (漂浮仓) together with an electronic shark repellent (驱逐装置) that can be dropped into the water in cases where swimmers are in severe trouble, trapped in a rip, or if there are sharks close by.

    In January 2018, the Westpac Little Ripper Lifesavers was used to rescue two young swimmers caught in a rip at Lennox Head, NSW. The drone flew down the beach some 800 meters from the lifeguard station, and a lifesaving flotation pod was dropped from the drone. The complete rescue operation took 70 seconds.

    We believe Shark Spotter is a win-win for both marine life and beachgoers. This unique technology combines dynamic video image processing AI and advanced drone technology to creatively deal with the global challenge of ensuring safe beaches, protecting environments, and promoting tourism.

Earthworms don't move fast. But humans can accelerate the worms' spread. Fishermen often use invasive(蔓延性的) earthworms to catch fish. Many have introduced invasive earthworms to rivers, streams and lakes previously unexposed to these animals. Gardeners who use earthworms to make their soil rich may unknowingly introduce invasive ones. The worms even give rides in the mud on wheels, potted plants and road materials shipped around the nation.

But they're not everywhere yet. In the Great Lakes region, "20 percent of the land is earthworm-free," says Cindy Hale, a research biologist. Of the remaining 80 percent of land, half of the land has fewer than two earthworm species-meaning there isn't yet too much impact on the ecosystem, she explains. For these regions, she says, now is the time to take action. According to Hale, educating the public, especially fishermen, is one approach to stopping the spread of invasive earthworms. Identifying which lands are currently earthworm-free is another.

Ryan Huefimeier, a program coordinator for Great Lakes Wom Watch, has been working on a model that will help create large maps of areas with minimal(最小的) or no damage from earthworms. Ultimately, landowners can use it to identify earthworm activity on their property. once identified, lands with minimal or no earthworm damage should be protected.

But scientists suspect that once invasive earthworms arrive they can't be removed. And even if all could be, affected forests might never return to the way they were. "It's very much a story of learning to live with them," concludes Lee Frelich of the University of Minnesota's Center for Forest Ecology.

Forest ecologists have called earthworms "ecosystem engineers" because they can change or create habitats that otherwise would not be present. Whether this is a good thing depends on the situation.

"What the earthworms do and how we value it is what really matters." said Hale. "In one place-farm fields or gardens-we really like European earthworms and what they do, so we consider them good. In native hardwood forests, we really don't like what they do-so we consider them bad. You really have to understand how an organism(微生物) affects an ecosystem. Things aren't black and white."