When people today talk about a tiny house, they probably mean the trendy living space that's about the size of a shed (棚). But you would have to be five inches tall to live in the original tiny houses. Dollhouse(小房子)，which have been around for several centuries, don't offer shelter to real people, but they provide a vivid（生动的） experience of life in times and places both real and imaginary.

    The National Building Museum in Washington, D.C., lets visitors time travel in this tiny world through ―Small Stories: At Home in a Dollhouse,” an exhibit that opened Saturday. Visitors can see twelve dollhouses from the Victoria and Albert Museum in London, England, which contain amazing tiny furnishings. But those people who put together the exhibit also wanted visitors to know the characters inside.

    “It's 300 years of British homes told through their inhabitants (居民),” said Alice Sage, who is in charge of the London museum.

    So as visitors look inside the Tate Baby House, a fancy townhouse from 1760, they can push a button to hear a young woman get a lecture from her mother on the proper way to run a home. In the Killer Cabinet house, a servant named Betsy complains about the problems of city life in the 1830s. “We've got the cat to keep the rats away,” she says.

    That dollhouse was John Killer's gift to his wife and five daughters. The girls were allowed to play with the house, but they probably also learned a few lessons, Sage said.

    “The kitchen of the house would have been the perfect way to teach the girls about the management of a home,” she said, noting the tiny dishes and pots.

    Those who prefer a more modern look won't be disappointed. There are two rooms displaying a white dollhouse from 1935, an apartment house from the 1960s and a brightly colored 21st-century design.

    The end of the exhibit shows how imaginative design sometimes works best in small spaces.

    The Building Museum asked twenty-four artists, designers and architects from across the United States to each create a “dream room” from the past, present or future. Some of these unique small rooms were made using traditional furnishings, others from materials such as clay, insects, 3D-printing, and even peeps marshmallow candies!

    Almost every machine with moving parts has wheels, yet no one knows exactly when the first wheel was invented or what it was used for. We do know, however, that they existed over 5,500 years ago in ancient Asia.

    The oldest known transport wheel was discovered in 2002 in Slovenia. It is over 5,100 years old. Evidence suggests that wheels for transport didn't become popular for a while, though. This could be because animals did a perfectly good job of carrying farming tools and humans around.

    But it could also be because of a difficult situation. While wheels need to roll on smooth surfaces, roads with smooth surfaces weren't going to be constructed until there was plenty of demand for them. Eventually, road surfaces did become smoother, but this difficult situation appeared again a few centuries later. There had been no important changes in wheel and vehicle design before the arrival of modem road design.

    In the mid-1700s, a Frenchman came up with a new design of road—a base layer (层) of large stones covered with a thin layer of smaller stones. A Scotsman improved on this design in the 1820s and a strong, lasting road surface became a reality. At around the same lime, metal hubs (the central part of a wheel) came into being, followed by the pneumatic tyre(充气轮胎) in 1846. Alloy wheels were invented in 1967, sixty years after the appearance of tarmacked roads (柏油路). As wheel design took off, vehicles got faster and faster.

    This is a true story that happened in Japan. In order to repair the house, a Japanese tore open the walls. Japanese houses normally have an empty space between the wooden walls. When pulling down the walls, he found that there was a lizard(蜥蜴) staying there because a nail(钉子) from outside was hammered into one of its feet. He saw this, feeling pity and curious. When he checked the nail, he found it was nailed 10 years ago when the house was first built.

    What happened? The lizard had survived in such a position for 10 years! It has been in a dark wall partition(夹层) for 10 years without moving! Then he wondered how this lizard survived for 10 years without moving a single step—since its foot was nailed! So he stopped his work and observed the lizard: What has it been doing? What and how has it been eating? Later, he didn't know from where another lizard appeared, with food in its mouth. Ah! He was astonished and touched deeply. The free lizard had been feeding it for the past 10 years.

    Such love, a beautiful love! Such love happened with this tiny creature… What can love do? It can do wonders! Just think about it: one lizard had been feeding the other for 10 long years, without giving up hope on its partner. If a small creature like a lizard can love like this, just imagine how we can love if we try.

    My son has poliomyelitis (小儿麻痹)and he suffered from it a lot. When he was young, my wife and I took him to see so many doctors and got different kinds of treatments. But still, he couldn't walk like a normal kid.

    So he was laughed at by his peers for his walking style. His tears burnt our eyes like sulphuric acid (硫酸 ). Then, he became afraid of going to school. He wouldn't go anymore.

    One night, my wife had a breakdown and shouted at him, “I tell you, my kid, you might be like this forever. You are a freak in other people's eyes, and perhaps it would never change. But in my eyes, in your dad's eyes, you are not a freak! You are not! Even if you are, we love you and we will love you forever!” My son spoke nothing for two days. He didn't eat or sleep. We could read he was hurt. We hoped something wonderful would fall in our family. On the third morning, he struggled to walk to my car, with his school bag in his hand of course. He raised his head high and hugged me, saying “want to go to school. Nothing will beat me.”

    You know, from then on, he was never afraid of being mocked or despised anymore. If he couldn't avoid these looks, he chose to look at them in the eyes. Later, something nice really happened and my son went to MIT. When he was asked how he managed to bear the pressure, he said, “Because of my parents.”

    My dear fellows, if you care too much about how other people look at you or what their opinions are, you will never become what you want to be.

    In the fight to conserve tropical rainforests, here's a tool you don't often hear about orange peels. Specifically, 12,000 tons of them, dumped (倾倒) on the land. “You don't usually associate waste treatment with biodiversity benefits, something that's good for the environment.

    Tim Treuer is an ecologist at Princeton University, and he's talking about a unique conservation story. It started in the early 1990s, when an orange juice producer called Del Oro set up a company near the Guanacaste Conservation Area in Costa Rica, a region that contains several national parks and a wildlife protection zone.

    Del Oro needed somewhere to dump the orange peels, and the company also owned forested land next to the parkland that it had no intention of growing crops on. So a deal was struck: if Del Oro donated its forested land, it could dump orange peel waste on degraded(退化的) land within the conservation area. Then a thousand dump trucks' worth of orange peels were lying on the land in 1998. “And within about six months the orange peels had been turned from orange peels into this thick black rich soil.”

    “I couldn't even find the site the first time I saw it.” He couldn't find it because, over 16 years, the orange peel waste had sent the land on a journey to become a vine-choked jungle, with three times the diversity of tree species of the neighboring control plot, richer soil and a much thicker covering. In other words, the experiment was a success. The results appear in the journal Restoration Ecology.

    Treuer says perhaps this lesson could be applied elsewhere. “It's a shame that we live in a world with nutrient-limited degraded ecosystems and also nutrient-rich waste streams. We'd like to see those things come together a little bit. That's not license for any agricultural company to just start dumping their waste products on protected areas, but it does mean that land managers, people involved with industrial-scale agricultural operations should start thinking about ways to do thoughtful experimentation to see if in their particular system they can have similar win-win-win results.”

    Joey was born in 1990 in Connecticut and now lives in North Carolina in the United States. When Joey was six, he started racing small cars in competitions. He began to win many races, but they weren't big races. His parents decided to move to Atlanta, Georgia, so Joey could compete in bigger and better competitions. When he was 12, he set a record by winning 14 races in a row at the Atlanta Motor Speedway. He continued to win many races, and finally began racing with regular-sized (正常大小的) race cars.

    When Joey was 15 years old, he met the race car driver Mark Martin. Martin is a famous NASCAR driver. NASCAR is the National Association for Stock Car Auto Racing, and it is the biggest and most popular car-racing organization in the United States. Martin was interested in Joey and thought he was “the real deal.” He said, “I am sure that he can be one of the greatest that ever raced in NASCAR. There's no doubt in my mind.”

    Martin was right. Joey started as a NASCAR driver in 2007. NASCAR has many races, and at first, Joey was only able to compete in smaller races because of his age. In his first NASCAR season, he won a championship (冠军). In 2008, he was able to compete in bigger NASCAR competitions. He competed in one of the top NASCAR racing series called the Nationwide Series, and at 18, he became the youngest winner in Nationwide Series history.

    In 2009, he became the youngest winner in another top NASCAR racing series called the Sprint Cup Series, and he also won the Nationwide Series for the fifth time. To be one of the best drivers in the history of racing, Joey has to win many more races. But at 19, he's off to a good start.