Breakthroughs in science and technology are paving the way for modern cities to support bigger populations. Now, we see the most exciting urban innovations to show you exactly how they'll improve your city's infrastructure(基础设施).

Lighting Up The Night

    Anthony Di Mari dreamed up an electric tree to help irrigate public parks and light them at night. These electric trees contain a special infill (填充物) that collects water from rainfall. The water is then distributed through a shallow underground irrigation system with the help from the trees' swaying movement. An electric motor turns energy from the waving of the artificial trees into electricity, which is used to light up the trees' outer LEDs.

Thinking Outside The Box

    As more people flock to urban areas, city planners will need to get increasingly creative about how to satisfy residents' health and transportation needs within decreasing available space. One way to achieve this is by updating infrastructure to support biking and walking by building suspended(悬浮的) roundabouts like hovering in the Netherlands. By lifting bicycle and pedestrian traffic above busy roadways, cities can significantly decrease over-crowded traffic condition.

Waving Hello To Clean Energy

    Cities that don't receive enough sunlight may find an attractive alternative in wave power. Since ocean waves rarely experience disruption(中断), electric engines driven by their clockwork push-and-pull can reliably provide power throughout the year. Further, thanks to advances in wave power technology, engineers have been able to move wave power engines farther offshore, where the waves pack the most punch, making the engines extremely efficient. So in the future, heavily populated coastal cities may use wave to meet their energy needs.

    We've reached a strange—some would say unusual—point. While fighting world hunger continues to be the matter of vital importance according to a recent report from the World Health Organization (WHO), more people now die from being overweight, or say, from being extremely fat, than from being underweight. It's the good life that's more likely to kill us these days.

Worse, nearly 18 million children under the age of five around the world are estimated to be overweight. What's going on?

    We really don't have many excuses for our weight problems. The dangers of the problem have been drilled into us by public ­health campaigns since 2001 and the message is getting through—up to a point.

    In the 1970s, Finland, for example, had the highest rate of heart disease in the world and being overweight was its main cause. Not any more. A public ­health campaign has greatly reduced the number of heart disease deaths by 80 per cent over the past three decades.

    Maybe that explains why the percentage of people in Finland taking diet pills doubled between 2001 and 2005, and doctors even offer surgery of removing fat inside and change the shape of the body. That has become a sort of fashion. No wonder it ranks as the world's most body ­conscious country.

We know what we should be doing to lose weight—but actually doing it is another matter. By far the most popular excuse is not taking enough exercise. More than half of us admit we lack willpower.

    Others blame good food. They say: it's just too inviting and it makes them overeat. Still others lay the blame on the Americans, complaining that pounds have piled on thanks to eating too much American­ style fast food.

    Some also blame their parents—their genes. But unfortunately, the parents are wronged because they're normal in shape, or rather slim.

    It's a similar story around the world, although people are relatively unlikely to have tried to lose weight. Parents are eager to see their kids shape up. Do as I say—not as I do.

    Despite what so many people would love to believe，NASA hasn't discovered any evidence of past or present intelligent life on Mars. Therefore, when the Curiosity rover  (好奇号探测器)found something suspicious on the Red Planet's surface, they were not only surprised but also a little bit worried.

    The thin fragment (碎片)was suspicious enough to guarantee its own name, with NASA's Curiosity rover team calling it the “Pettegrove Point Foreign Object Debris，” named for where it was discovered. With no idea what it was or where it came from, the rover's handlers began to worry that it might actually be a piece of the rover itself，suggesting some unseen damage or other issue with the robot. Thankfully，those concerns seem to have been unfound.

    In a new update from NASA the object has now been identified as a natural piece of rock rather than a piece of any man-made craft or vehicle. The team analyzed the unusual object with a tool called the Chem Cam RMI. The instrument uses a laser (激光器)to sniff out the makeup of anything that is pointed at, and the results for this particular piece of debris revealed that it's actually just a very thin piece of rock.

    NASA describes the inspection: The planning day began with an interesting result from the previous plan's Chem Cam RMI analysis of a target that was referred to as “Pettegrove Point Foreign Object Debris”(PPFOD)，and supposed to be a piece of spacecraft debris fact. In fact it was found to be a very thin slice of rock, so we can all rest easy tonight. Curiosity has not begun to shed its skin!

    How this particularly thin sliver of rock got to where it is—and why it seems to be a different colour than the surrounding sand and debris—remains unexplained, but at least the rover isn't falling apart.

    Twenty-one years ago, my husband gave me Sam, an eight-week-old schnauzer（雪纳瑞犬）, to help ease the loss of our daughter. Sam and I developed a very special bond over the next years.

    At one point, my husband and I decided to move to a new home in New Jersey. Our neighbor, whose cat had recently had kittens, asked if we would like one. We were a little apprehensive about Sam's jealousy and how he would handle his turf（地盘）being invaded, but we decided to risk it.

    We picked a little, gray, playful ball of Fur. She raced around chasing imaginary mice and squirrels and jumped from table to chair in the blink of an eye, so we named her Lightning.

    At first, Sam and Lightning were very cautious with each other and kept their distance. But slowly, Lightning started following Sam — up the stairs, down the stairs, into the kitchen. Later, when they slept, it was always together; when they ate, it was always next to each other. When I took either one out, the other was always waiting by the door when we returned. That was the way it was for years.

    Then, without any warning, Sam was diagnosed as having a weak heart. I had no other choice but to have him put down. The pain was nothing compared with what I experienced when I had to walk into our house alone. This time, there was no Sam for Lightning to greet and no way to explain why she would never see her friend again.

In the following days, Lightning seemed heart-broken. I could see the disappointment in her eyes whenever anyone opened the front door, or the hope whenever she heard a dog bark.

    One day as I walked into our living room, I happened to see Lightning was lying next to the sculptured replica（复制品）of Sam that we had bought a few years ago, one arm wrapped around the statue's neck, contentedly sleeping with her best friend.

    Many years ago, my mother read from the book Blueberries for Sal by Robert McCloskey to me. I remember as if it were yesterday, hearing her voice at my side on a cold wintry night. My mother's voice changed my world.

    Long before I could read on my own, she shared with me the strength and beauty of McCloskey's language a story of a little girl and her mother out in nature, co-existing with a mother bear and her own baby. The power of the story, of language and of my mother all came together. And it happened many times after that, over and over. The read aloud made me a reader.

    Years later, I was reading aloud a picture book to a small child in a classroom. His life, so far, had not been easy. His childhood was troubled by poverty and loneliness. In that moment, in the joy of the read aloud, he had an idea that started something big.

    What he said was this: "Mrs. Allyn, let's make sure everyone knows how good this feels. Let's have a holiday for the read aloud" Therefore, my organization, LitWorld, created a grassroots movement World Read Aloud Day in 2010 to honor this young boy's wish for everyone to be able to have a read aloud every day.

    Since the day he shared that good idea with us, World Read Aloud Day has become a worldwide event reaching over one million people in more than 65 countries around the world. This year we are over 600 cities strong, a number that is growing every day.

    Children who grow up as readers become engaged citizens of the global world, and every child deserves the right to read. When I say that reading aloud will change the world, I know it sounds simple. But one of the many great things about giving kids access to the power of stories and sharing them together is that it is simple. It is also cheap and easily done. And the impact is huge.

    People from all over the world visit Disneyland to have fun, not to get sick. But last week, an outbreak of measles(麻疹)spread from the Southern California theme park. As of Monday, January 19, at least 52 people have got the easily spread illness.

    The majority of the reported cases of measles are from people who visited the park before. According to the California Department of Public Health, these people were exposed to the illness at Disneyland from December 17-20.

    Officials believe the cause is likely someone who caught measles abroad and visited Disneyland, but this has yet to be proved. However, in 2014, California had its highest measles infection rate in nearly twenty years. There were 66 cases of measles reported in the state―23 of them in Orange County, where Disneyland is located.

    Measles spreads very easily. It can be caught from coughing and sneezing. Crowded areas like theme parks are especially suitable for its spread.

    The illness starts with a fever and develops into symptoms including a cough, runny nose, red eyes and so on. About three out of ten people infected with measles will develop another health problem, including an ear infection or pneumonia(肺炎).

    The best way to guard against measles is to get vaccinated(打疫苗). An unvaccinated person is 35 times more likely to catch measles than someone who received a vaccination.