How old are the apps on your smartphone? Is it time for an update? Here are three apps for you. Try them out and have fun.

Duolingo

    Learning a foreign language doesn't always mean you have to sit in a class and take endless exams. An app called Duolingo has been designed to help you memorize (记住) new words and grammar in creative ways，such as online lessons，games and interesting exercises. For example，one exercise asks you to put words in the right order to make the correct sentence. You can also try translation practice.

Douban FM

    A music app is a necessity for almost every smartphone now. Douban FM might be the right thing for you.

    There is no playlist on Douban FM--songs just keep streaming (播放) one by one. You can use the “heart”, “trash” and “skip” buttons (按钮) to mark the songs you like，don't like and want to cut short, respectively (分别地). Those marked with a heart will be stored in another list as your favorites for you to listen to anytime you want. Douban FM also has different channels (频道). There are many types of music, such as blues, jazz, and pop. You can choose the music for outdoor activities, work or studying depending on your mood (心情).

Flipboard

    It is one of the hottest news apps right now. With Flipboard, you can make everything personal to you. All you have to do is open up the app, “flip through” to select whatever interests you，and click the “+” button. At the end you'll have your own magazine, complete with a front page, new articles, and information.

    One day a few years ago, a very funny thing happened to a neighbour of mine. He is a teacher at one of London's big medical schools. He had finished his teaching for the summer term and was at the airport on his way to Russia to give a lecture.

    He had put a few clothes and his lecture notes in his shoulder bag , and he had put Rupert , the skeleton (人体骨架）to be used in his lecture , in a large brown suitcase. At the airport desk, he suddenly thought that he had forgotten to buy a newspaper. He left his suitcase near the desk and went over to the shop.

    When he got back he discovered that someone had taken his suitcase by mistake. He often wonders what they said when they got home and found Rupert.

    The third week of SEAL training means Hell Week. It is on Wednesday of Hell Week that you paddle down to the mud flats（泥滩） and spend the next 15 hours trying to survive the freezing-cold mud, the howling wind and the increasing pressure from the instructors to quit. As the sun began to set that Wednesday evening, my training class, having broken the rules, was ordered into the mud. The mud consumed each man till there was nothing visible but our heads. The instructors told us we could leave the mud if only five men would quit—just five men and we could get out of the extreme cold.

    Looking around the mud flat, it was apparent that some students were about to give up. It was still over eight hours till the sun came up--eight more hours of freezing cold. The chattering teeth and shivering moans (呻吟）of the trainees were so loud that it was hard to hear anything. And then, one voice began to echo (回荡）through the night--one voice raised in song. The song was terribly out of tune, but sung with great enthusiasm. One voice became two, and two became three, and before long everyone in the class was singing. We knew that if one man could rise above the great suffering then others could as well. The instructors threatened us with more time in the mud if we kept up the singing—but the singing went on. And somehow, the mud seemed a little warmer, the wind a little less bitter and the dawn not so far away.

    If I have learned anything in my time traveling the world it is the power of hope. The power of one person, Washington, Lincoln, King, Mandela and even a young girl from Pakistan, Malala, can change the world by giving people hope.

    So, if you want to change the world, start singing when you're up to your neck in mud.

    A Chinese scientist's attempt to produce the world's first gene-edited babies who are immune to HIV has caused floods concern.

    In an online video posted on Monday, He Jiankui, a biological researcher, announced that a pair of twin baby girls, Lulu and Nana, was born healthy a few weeks ago with genetic editing technology that can prevent them from being infected with HIV.

    He, who was believed to be in Hong Kong on Monday to attend the Second International Summit on Human Genome Editing, could not be reached for comment. But his announcement sparked a heated argument concarning medical ethics（伦理）and effectiveness.

    The Shenzhen Health and Family Planning Commission said on Monday evening that it had not received any ethical assessment application for the study, which is required as a prior condition for such experiments.

    More than 120 scholars from universities and institutes with high status from China and abroad,such as Tsinghua University and the Massachusetts Institute of Technology (MIT),strongly condemned the research in a signed statement, saying the “research” lacks effective ethics inspection, and it amounts to human experimentation,which is “crazy”.

    In the statement, published on Sina Weibo, the scientists said any attempt to make changes to human embryos with genetic editing and give birth to such babies involves high risk as an inevitable part, due to inaccuracies in existing genetic editing technologies.

    “Scientists all over the world dare not make such attempts due to the huge risks and more importantly, ethics. The government must make quick legal moves to strictly supervise（监督）such research. The Pandora's Box has been opened, and we may still have a chance of closing it before it is too late,”the statement said.

    Tsui Lap-chee, president of the Academy of Sciences of Hong Kong, said a lot of issues may occur in gene editing. If one gene is edited, it will affect others that interact with it. And the whole genome, a collection of genes, may also be affected.

    We've heard of robots and AI (Artificial Intelligence) taking human jobs, but I bet mayors（市长）don't really think their jobs can be threatened any time soon. They were wrong, and the AI running for the mayor of a Tokyo district was clear proof of that.

    AI can't legally run for high-ranking public management positions yet, but one mayoral candidate from Tama City, Tokyo, intended to maximize the use of artificial intelligence in running city affairs. He was running his campaign (竞选运动) as "AI Mayor". Basically, he was suggesting replacing human public officials with AI and having them collect city data and create fair and balanced policies that will benefit everyone.

    "For the first time in the world, AI will run in an election," human candidate Michihito Matsuda announced on Twitter. "Artificial Intelligence will change Toma City. With the birth of an AI Mayor, we will conduct balanced politics."

    The AI Mayor was campaigning very much like its human competitors. Posters were shown all over Tama City and campaign trucks were blaring out(大声鸣响)promises of an AI utopia (乌托邦)and asking for support.

    Some people called Michihito Matsuda's campaign a stunt (噱头), as a human would still be the one legally in charge. However, others said that they were excited about the future of AI running things in the background, adding that it had to be a better choice.

In the story of "The crow and the Pitcher" from Aesop's Fables, a thisty crow (乌鸦)drops stones into a narrow jar to raise the low level of water inside so he can take a drink.

Now scientists have evidence to back up that story. Crows actually do understand how to make water displacement (移位) work to their advantage, experiments show. The results suggest that the birds are, at least in some aspects, as smart as first-graders.

Researchers, led by Sarah Jelbert at the University of Auckland in New Zealand, presented six crows with tubes filled with water. Inside the tubes, a worm or piece of meat on a piece of wood was floating, just out of reach of the crow. In front of the tubes, the researchers arranged several rubber erasers that would sink, and some plastic objects that would float. The crows found out that they could drop the erasers into the tubes in order to raise the water level and get their snack.

However, the birds handled awkwardly in experiments in which they could choose to drop objects in either a wide tube or a narrow one to get a snack, the researchers said. Dropping objects into narrow tube would lift the water level by a greater amount and put the treat within reach after just two drops; while it took around seven drops to raise the snack to the same level in the wide tube. The crows obviously didn't realize this, and most of them went for the wide tube first.

Previous studies showed that chimps and human children can solve similar tasks. In a 2011 study, chimps and kids found out that they could put water into a tube to reach a peanut that was floating in a small amount of water at the bottom.