Last week, my granddaughter started kindergarten, and I wished her every success. But part of me didn't. I actually wanted her to fail in some ways because I believe that failure can be good for our learning process. Success is proving that you can do something that you already know you can do, or doing something correctly the first time, which can often be a problematic (存在问题的) victory. First-time success is usually a fluke (侥幸). First-time failure, however, is supposed to be the natural order of things. Failure is how we learn.

    In Africa they describe a good cook as “She who has broken many pots.” If you've spent enough time in the kitchen to have broken a lot of pots, probably you know a fair amount about cooking. I once had dinner with a group of cooks, and they spent time comparing knife wounds and burn scars. They knew how much credibility (可信) their failures gave them.

    I earn my living by writing a daily newspaper column. Each week I know that one column I write is going to be the worst column. I try my best every day. I have learned to love that column. A successful column usually means that I am discussing my familiar topic, writing in a style I am used to or saying the same things as anyone else but in a better way.

    My younger daughter is a trapeze artist (荡秋千演员). She spent three years practising a show, and she did it successfully for years. There was no reason for her to change it but she did anyway. She said she was no longer learning anything new and she was bored. And if she was bored, there was no point in subjecting (使……服从于) her body to all that stress. She risked failure and great public embarrassment in order to feed her soul.

    My granddaughter is a perfectionist. She will feel her failures, and I will want to comfort her. But I will also, I hope, remind her of what she learned, and how she can do better next time. I hope I can tell her, though, that it's not the end of the world. Indeed, with luck, it is the beginning.

    Mandara seemed to know something big was about to happen. So she let out a yell, caught hold of her 2-year-old daughter Kibibi and climbed up into a tree. She lives at the National Zoo in Washington D.C.

    And on Tuesday, August 23rd, witnesses said she seemed to sense the big earthquake that shook much of the East Coast before any humans knew what was going on. And she's not the only one. In the moments before the quake, an orangutan (猩猩) let out a loud call and then climbed to the top of her shelter.

    “It's very different from their normal call,” said Brandie Smith, the zookeeper. “The lemurs (monkey like animals of Madagascar) will sound an alarm if they see or hear something highly unusual.”

    But you can't see or hear an earthquake 15 minutes before it happens, can you? Maybe you can——if you're an animal.

    “Animals can hear above and below our range of hearing,” said Brandie Smith. “That's part of their special abilities. They're more sensitive to the environment, which is how they survive.”

    Primates weren't the only animals that seemed to sense the quake before it happened. One of the elephants made a warning sound and a huge lizard (蜥蜴) ran quickly for cover. The flamingoes (a kind of birds) gathered before the quake and stayed together until the shaking stopped.

    So what kind of vibrations (震动) were the animals picking up in the moments before the quake? Scientist Susan Hough said earthquakes produce two types of waves——a weak “P” wave and then a much stronger “S” wave. The “P” stands for “primary”. And the “S” stands for “secondary”. She thinks the “P” wave might be what sets the animals off.

    Not all the animals behaved unusually before the quake. For example, Smith said the zoo's giant pandas didn't jump up until the shaking actually began. But many of the other animals seemed to know something was coming before it happened. “I'm not surprised at all,” Smith said.

    Tourism is often about seeking deeper emotional and personal connections with the world around us. Not all travel experiences, however, need to take place in the real world. With the evolution of virtual reality (VR) technology, tourism will increasingly become a combination of physical and virtual worlds. VR may even remove the need to travel entirely.

    But can a VR experience really equal a real world one? Many experts believe it can. Studies have shown that our brains have an inbuilt VR-like mechanism that enables us to live imagined experiences. Much of our waking life is spent thinking about either the past or the future. This is known as" mind wandering". During these events we're not paying attention to the current world around us. Instead, we're recalling memories, or creating and processing imagined futures.

    When engaged in mind wandering, our brains process these mental images using the same pathways used to receive inputs from the real world. So, the imagined past or future can create emotions and feelings similar to how we react to everyday life. VR can create these same feelings.

    While critics might argue that a virtual experience will never match reality, there are several ways VR tourism could make a positive contribution. Firstly it could help protect sensitive locations from over-tourism. In recent years famous sites such as Maya Bay in Thailand, and Cambodia's Angkor Wat Temples have had to limit the number of visitors because of their negative impact. These places are now producing their own VR experiences that will allow tourists to pass through virtual models of the sites.

    Virtual reality may also allow people back in time, to experience historical events, visit ancient cities, and even to walk among dinosaurs.

    Finally, in a world where many people suffer from stress and depression due to overwork, virtual tourism may provide a cheap and convenient way for people to take brief holidays to otherwise unreachable destinations and recharge their batteries, without ever leaving their homes.

    It sounds like science fiction but it's already happening. As virtual technology improves and as people continue to demand new and interesting experiences, expect more virtual tourism, both in combination with the real world and instead of it.

    Lima, the capital of Peru (秘鲁), has countless museums that tourists can't afford to miss. Now start packing up and prepare for your perfect Peruvian history exploration at these wonderful museums.

    ◆Larco Museum

    Stepping inside, visitors get to learn the 5,000-year history of Peru through an unbelievable collection of objects. The best thing about the museum is that it keeps the door to the storeroom open to visitors so that they can admire its collection closely.

    ◆Gold Museum of Peru

    If you like shiny objects or precious metals, then plan a trip to the Gold Museum of Peru. In ancient times, the Peruvian people were celebrated for their skills in metals. And the museum is aimed at preserving this heritage.

    ◆Lima Art Museum

    Art experts are much pleased as the city is also home to the Lima Art Museum. Its permanent exhibit of over 1, 200 pieces is merely a small part of its amazing collection of more than 17, 000 artifacts. The highlight of the museum is its collection of Carlos Baca-Flor's masterpieces, which is considered to be the most complete set in the world.

    ◆Museum of Italian Art

    The only museum dedicated to European art in Peru, the Museum of Italian Art is a storehouse of classical and contemporary paintings and sculptures belonging to the 20th century. The property is easily accessible by a short walk from the Lima Art Museum.

    ◆Museum of Natural History

    Last but certainly not least is the Museum of Natural History. Giving a glimpse into the rich biodiversity in Peru, the museum has on display the skeletons of a sperm whale and fossils of several mammals.

    Nelle Harper Lee was born on April 28,1926. Since Lee's mother was mentally ill, she was raised by her father. She became very close to her father.

    The naughty Lee loved reading, and would make up stories with Truman, her neighbour who was two years older than her. Seeing her daughter's imagination, Lee's father gave her a typewriter.

Before her final year in the university of Alabama, Lee dropped out to become a writer. She moved to New York City where her childhood friend Truman was already established as a famous writer. While there, she worked on her first book—To Kill a Mockingbird. It won her the Pulitzer Prize in 1961 and was made into an Academy Award winning movie the following year. To Kill a Mockingbird tells the story of six-year-old Scout and her brother who lived in the town of Maycomb Alabama with their single father Attics. Attics is a lawyer who defends the blacks. At a young age, Scout is exposed to the terrors of segregation(宗族隔离)。Then, in 2014, the first draft of a new book—Go Set a Watchman was discovered among Lee's papers. It is the story of 26-year-old Scout who returns to Maycomb to visit her father. She is shocked to find her father a changed man. Attics has turned into a segregationists! The story shows the mixed feelings Scout has for the changes that have taken place in her hometown and father.

    A loner for most of her life, Lee stayed unmarried, preferring to lead a small town life. On February 19, 2015, Lee passed away at the age of 89.

On paper, hydrogen (H2) looks like a dream fuel. Coal, oil, and natural gas produce carbon dioxide, which warms the earth when burned, Hydrogen produces pure water. Hydrogen packs more energy into less space than a battery (but certainly less than petrol) . Also, empty tanks (燃料箱) can be refilled with hydrogen much faster than refilling empty batteries with electricity.

While in practice, things are trickier. Storing a meaningful amount of hydrogen gas requires pressing it several hundred-fold. Changing it into the liquid form is another option, but it should be cooled to-253C. Both processes require a heavy and strong tank. While a 700 bar tank is acceptable for a city bus or a truck, adapting it for use in small vehicles is very difficult because the pressure during refilling would be too great.

The solution? Powerpaste.

A German team of researchers, led by Marcus Vogt, have come up with an interesting "powerpaste", which can store hydrogen energy at atmospheric pressure, ready for release when needed. It is so named because it comes in tubes and looks like toothpaste (牙膏) , not in its traditional form of gas.

The main ingredient (原料) of the paste is magnesium hydride, a substance that reacts with water to form hydrogen. The escaped hydrogen can then be directed into a fuel cell, where it reacts with oxygen from the air to produce electric power.

Refueling is very simple, as instead of going to a filling station, drivers and riders can simply replace an empty tube with a new one and refill the water tank.

Given that powerpaste only begins to break down at temperatures of around 250℃ it remains safe even when a vehicle stands in the baking sun for hours.

However, we will have to be patient. Just because researchers have succeeded in developing a new fueling way does not mean that we can expect to see such vehicles on the road anytime soon. It will indeed be several years before this concept is turned into reality.