Students at the Calhoun School in New York City have much more than a roof over their heads. They have a rooftop garden, with lush grass, colorful flowers and fragrant herbs. "Green roofs" are sprouting up all over, from schools to city skyscrapers. And roofs aren't the only things going green. Architects are finding all sorts of new ways to build buildings that are easier on the environment. These schools, homes, and offices are called "green buildings".

Normally it takes a lot of energy to run appliances. Too often, that energy comes from burning fossil fuels. So green buildings are designed to do all these things with much less energy. An energy-smart building starts with thick walls. A layer of insulation (隔热材料) traps air to stop heat from passing through. That keeps heat inside in the winter, and keeps heat outside in the summer. This saves energy for heating and cooling.

Heat pumps are another power-saving way to stay comfortable. A ground heat pump moves heat through pipes that run through the ground next to the building. A few feet under the ground, the temperature stays around 10℃ all year round. Water flowing around the pipes helps heat the building in winter and cool it in summer.

Another way to build green is to use recycled materials. That saves the cost and pollution of manufacturing something new. In the Chicago Center for Green Technology, the ceiling tiles (瓷砖) are made of pressed newspaper. The bathroom floors are tiled with recycled glass, and the stall walls are recycled plastic. Builders have found many creative ways to re-use old materials.

As more people become concerned about climate change, more buildings are going green. Green buildings produce less of the gases that warm the planet. City planners like green buildings because they save money. And they are healthier for the people who work and live inside. But you don't need to build a whole new building. Simple changes like shading windows and planting trees can make any home greener—and a better Earth home for us all.

Five-year-old Willard Wigan struggled to tell the difference between an M and a W or a 6 and a 9. Unfortunately, his schoolteacher knew nothing about dyslexia(阅读障碍症), a learning disability that can make letters and numbers confusing. She didn't try to help him. Not surprisingly, Willard didn't like school. Usually, his mind drifted—to playing outside, to his dog Maxie, or to the ants that lived near his family's garden shed. Willard was especially curious about those ants. He felt like them—small and insignificant. Thus, when he noticed some ants trying to build a house, he decided to help them! Willard constructed a little building. Then he sprinkled sugar inside to encourage the ants to move in. When they did, Willard built more houses.

At school, Willard still struggled, but now he knew he could do something special. Maybe he wasn't a failure after all. If he had trouble with his reading or math, Willard would later go home and created tiny furniture for the ant houses. He even built an ant school, with teeny swings, ladders, seesaws, and a merry-go-round. His artistic skill increased, and a love for little things began to grow in his heart.

At age nine, Willard began carving faces on toothpicks. He discovered that his ability improved when he held his breath as he worked. When he quit school at age 15 to help support his family, Willard still spent his spare time carving. His confidence grew as more people appreciated his talent. Eventually, he quit his factory job to pursue his dream of becoming one of the best artists in the world. Now, years later, Willard carves the tiniest artwork in the world! His sculptures are so small that several can fit on a period at the end of a sentence.

Because of their beauty and rarity, his sculptures have made Willard a wealthy man. But he says, "Success isn't about material things like an expensive watch or a costly ring; it's about persevering and achieving your dreams."

Willard Wigan, micro-sculptor, has done just that. The man who felt small as a boy has shown the world that something small can really be BIG.

Billions of people deal with a nail-biting habit at some point in their lives. Many will go to great lengths to try to stop. And while not all of us are nail-biters, most of us do have a habit we'd like to kick. So what's the best way to break one?

Research shows that intentions alone often fail to lead to long-term behavior change. This isn't to say you can't break a habit. Rather, by understanding the basis of habits, you can create better plans for changing them. For example, we know habits are often affected by environments and routines. Lying in bed may cause you to endlessly scroll through your phone, or watching TV on the couch may lead you to grab a sugary snack.

One of the most effective ways to manage behavior is to identify these locations or times of day. Then try to modify them by changing your routine or creating obstacles that make it more difficult to perform the habit in that space. Moving, switching jobs, or even starting a new schedule, are particularly great times to break a habit or build a new one.

One 2005 study tracked university students' exercising, reading, and TV-watching habits before and after they transferred schools. When students were no longer around old environments and routines, their habits, even the strong ones, significantly changed.

For behaviors like nail-biting, a practice called habit reversal training can be helpful. Developed by psychologists in the 1970s, the aim is to change a habit by replacing it with another one that's less detrimental. The training requires you to analyze and understand your habit cues, so you can effectively step in at the right times. For example, if you tend to bite your nails at work, keep a fidget toy at your desk in advance. Then, if a stressful email comes in, use the toy when you feel the urge to bite your nails.

Breaking a habit takes time, so remember to give yourself grace and have patience through the process.