Ever wonder how much a cloud weighs? What about a hurricane? A meteorologist（气象学家） has done some estimates and the results might surprise you.

    Let's start with a very simple white puffy cloud—a cumulus cloud(积云). How much does the water in a cumulus cloud weigh? Peggy LeMone, senior scientist at the National Center for Atmospheric Research in Boulder, Colorado, did the numbers. “The water in the little cloud weighs about 550 tons,” she calculates. “Or if you want to convert it to something that might be a little more meaningful...think of elephants.” Assume（假设） an elephant weighs about six tons, she says, that would mean the water inside a typical cumulus cloud would weigh about one hundred elephants.

    The thought of a hundred elephants' worth of water floating in the sky begs another question—what keeps it up there?

    “First of all, the water isn't in elephant-sized particles(微粒); it's in tiny tiny tiny particles,” explains LeMone. And those particles float on the warmer air that's rising below. But still, the concept of so much water floating in the sky was surprising even to a meteorologist like LeMone. “I had no idea how much a cloud would weigh, actually, when I started the calculations（计算）,” she says.

    So how many elephant units of water are inside a big storm cloud—10 times bigger all the way around than the “puffy” cumulus cloud? Again, LeMone did the numbers: About 200,000 elephants.

    Now, come to the calculations for a hurricane about the size of Missouri and the figures get really massive. “What we're doing is weighing the water in one cubic meter theoretically pulled from a cloud and then multiplying by the number of meters in a whole hurricane,” she explains.

    The result? Forty million elephants. That means the water in one hurricane weighs more than all the elephants on the planet. Perhaps even more than all the elephants that have ever lived on the planet.

    Many years ago, I made a living by driving a car. One night I went to pick up a passenger at 2:30 am. When I arrived to collect, I found the building was dark except for a single light in a ground floor window.

    I walked to the door and knocked.“Just a minute,” answered a weak, elderly voice.

    After a long pause, the door opened. A small woman in her eighties stood before me. By her side was a small suitcase.

    I took the suitcase to the car, and then returned to help the woman. She took my arm and we walked slowly towards the car.

    She kept thanking me for my kindness.“It's nothing,” I told her, “I just try to treat my passengers in the way I would want my mother treated.”

    “Oh, you're such a good man,” she said. When we got into the taxi, she gave me an address, and then asked, “Could you drive through downtown?”

    “It's not the shortest way,” I answered quickly.

    “Oh, I'm in no hurry,” she said.“I'm on my way to a hospice(临终医院). I don't have any family left. The doctor says I don't have very long time.”

    I quietly reached over and shut off the meter(计价器).

    For the next two hours, we drove through the city. She showed me the building where she had once worked, the neighborhood where she had lived, and the furniture shop that had once been a ballroom where she had gone dancing as a girl.

    Sometimes she'd ask me to slow down in front of a particular building and would sit staring into the darkness, saying nothing.

    At dawn, she suddenly said, “I'm tired. Let's go now.”

    We drove in silence to the address she had given me.

    “How much do I owe you?”she asked.

    “Nothing,” I said.

    “You have to make a living,” she answered.“Oh, there are other passengers, ”I answered.

    Almost without thinking, I bent and gave her a hug. She held onto me tightly. Our hug ended with her remark, “You gave an old woman a little moment of joy.”

    Happy,angry,amazed—these are some of the emotions we like to express these days when we're sending a message on our smartphones.That's a quick way of telling someone how we're feeling.Yes,emojis have become a vital tool for communication.

    The emoji was first invented in Japan in the late 1990s and the word "emoji" comes from the Japanese words for "picture" and "character".The number of different images has dramatically increased since then and now we have a picture for every mood or situation.

    So now we are giving this new creation the visual "thumbs-up" but have you thought why we've become so addicted to using emojis? Professor Vyv Evans has written a book called The Emoji Code, saying "increasingly, what we're finding is that digital communication is taking over certain aspects of face-to-face interaction...one of the reasons why emojis are so popular is that they really do enable us to express our emotional selves more effectively."

    Another advantage of emojis is that they are an international language—they don't use words but some pictures so they can be easily interpreted whatever your native language is. However, the emojis can sometimes be misinterpreted—if a friend sends you an emoji of a hammer, you may think he/she is angry when really he/she is saying he/she is clumsy!

    Emojis are a good way for showing similar feelings. But as linguist(语言学家) Neil Cohn says, "To many, emojis are an exciting evolution of the way we communicate, but to others, they are a linguistic Armageddon（大决战）."It does show there is a lot more to our communication than words alone but does this mean the decline in traditional writing?

Do you believe that things are connected for no scientific reason at all? For example, do you avoid saying the word "four" to avoid bad luck? If so, you have a superstition (迷信). And you're not alone – all kinds of people have them.

For example, Portugal's soccer superstar Cristiano Ronaldo always steps onto the pitch (球场) with his right foot first, according to The Telegraph. And sports players are not alone in having superstitions. A visitor once asked the Nobel Prize winning scientist Niels Bohr whether he really believed that the horseshoe he'd hung at his country home was lucky. "Of course not," the Danish physicist said. "But I understand it's lucky whether you believe in it or not."

One recent study found that even scientists at MIT and other top US schools tended to look for a meaning in natural events, similar to the connection between stepping on the pitch and playing soccer well, according to The Atlantic. When the researchers gave the scientists little time to answer questions, they were twice as likely to agree with statements such as "Trees produce oxygen so that animals can breathe" as they were when they had more time to think about their reply.

It seems that fear can make people think differently in this way, too. In a British study, students imagined meeting a "witch" who said she would cast (施魔法) an evil spell(符咒) on them. About half said a scientist should not be worried about the spell. Yet each of them said that, personally, they wouldn't let the witch do it to them.

So why are so many of us superstitious? Well, it seems to be our way of dealing with the unknown. "Many people quite simply just want to believe," Brian Crank, a professor of psychology at Missouri Western State University, said in a 2008 interview. "The human brain is always trying to work out why things happen, and when the reason is not clear, we tend to make up some pretty bizarre (古怪的) explanations."

    And these explanations aren't completely unhelpful. In fact, superstitions can sometimes work and bring real luck, according to psychologists at the University of Cologne in Germany in the May 2010 issue of the journal Psychological Science. They found that believing in something can improve performance on a task like an exam.

    So, what about you? What superstitions do you follow to keep you safe and successful?

    I can't think of a better way of appreciating a new culture than by taking part in one of its festivals. You'll find that some festivals are celebrated by an entire country, while others may be known only to a single city or region, but either way festivals play an important role in a certain culture. Just enjoy them!

    ★ Tomatina — Bunol, Spain

    Every last Wednesday in August, the town of Bunol is filled with tons of tomatoes in the world's biggest food flight. Many people wear goggles during this hour of great fun, as the town becomes a red river.

    ★ Boryeong Mud Festival — Boryeong, South Korea

    For two weeks in July, millions gather in Boryeong to experience the grey pools and slides. What began as a way to help sell the region's mineral-rich mud has turned into a festive party with music and fireworks. The mud is usually only available in cosmetic products (化妆品), but here you can cake yourself in grey as you want.

    ★ Holi — India

    Holi, the Festival of Colors, is a Hindu celebration full of joy and one of India's most important holidays. During the day of the last full moon of the lunar month, usually late February or early March, the air is full of brightly colored powder (粉末). The festival is celebrated differently throughout the country, with bonfires and music, but the cheerful spirit is common among Hindu people around the world.

    ★ International Pillow Fight Day — Worldwide

    Tens of thousands of people took part in the 4th annual International Pillow Fight Day on April 2,2013. From London to Vancouver to many other cities, the festival is held in more than 100 countries. So just bring a soft pillow in early April, and watch feathers fly.

（2023·浙江·高考真题）According to the Solar Energy Industry Association, the number of solar panels installed(安装)has grown rapidly in the past decade, and it has to grow even faster to meet climate goals. But all of that growth will take up a lot of space, and though more and more people accept the concept of solar energy, few like large solar panels to be installed near them. 

Solar developers want to put up panels as quickly and cheaply as possible, so they haven't given much thought to what they put under them. Often, they'll end up filling the area with small stones and using chemicals to control weeds. The result is that many communities, especially in farming regions, see solar farms as destroyers of the soil. 

"Solar projects need to be good neighbors," says Jordan Macknick, the head of the Innovative Site Preparation and Impact Reductions on the Environment(InSPIRE)project. "They need to be protectors of the land and contribute to the agricultural economy." InSPIRE is investigating practical approaches to "low-impact" solar development, which focuses on establishing and operating solar farms in a way that is kinder to the land. One of the easiest low-impact solar strategies is providing habitat for pollinators(传粉昆虫). 

Habitat loss, pesticide use, and climate change have caused dramatic declines in pollinator populations over the past couple of decades, which has damaged the U.S. agricultural economy. Over 28 states have passed laws related to pollinator habitat protection and pesticide use. Conservation organizations put out pollinator-friendliness guidelines for home gardens, businesses, schools, cities—and now there are guidelines for solar farms. 

Over the past few years, many solar farm developers have transformed the space under their solar panels into a shelter for various kinds of pollinators, resulting in soil improvement and carbon reduction. "These pollinator-friendly solar farms can have a valuable impact on everything that's going on in the landscape," says Macknick.