It's official. Denmark—as well as being the world's best country to live in for women with the second-happiest people and one of the best healthcare systems in Europe—has the most contented babies. Or, at least, the ones who cry the least. According to research published in the Journal of Pediatrics, Danish, German and Japanese babies cry the least, while British, Canadian and Italian babies cry the most.

    “I'm not surprised,” Danish parenting expert and co-author of The Danish Way of Parenting Jessica Alexander tells me. “The first year of a child's life is considered so important in Denmark. Danish parents are much less stressed because they get good maternity and paternity leave (孕产假). The atmosphere is much calmer and, if mothers are getting more time off, that goes hand in hand with less stress, more contact, more routines and less crying.” She pauses before throwing in a final tip: “Oh, and Danish babies sleep outdoors a lot.”

    In Denmark, a woman is given four weeks pregnancy leave followed by 52 weeks of paid leave that can be shared between parents. And Alexander thinks there is another important reason why Danish babies cry less: breastfeeding. “It's just the done thing in Denmark,” she says of a country that has the world's highest breastfeeding rates. “In other countries, there are continual discussions about whether you should or shouldn't breastfeed. In Denmark, breastfeeding has never gone out of style. And everyone does it for a year.”

    For Iben Sandahl, Alexander's co-author, it comes down to the Danish attitude to life in general. “We are an honest and pure people,” she tells me. “We are surrounded by social support and are less likely to become angry, sad or annoyed when our babies are crying. And we are good at embracing (拥抱) all kinds of feelings, so we aren't scared. Instead, we try to connect with the babies when they cry. It's how babies communicate and it's about trying to understand it.”

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    Were dinosaurs (恐龙) warm-blooded or cold-blooded? According to a new study, scientists have found that they were somewhere in the middle. This new study shows that dinosaurs were very different from most of today's animals that are either warm or cold-blooded.

    “I think we were all surprised by this,” said Felisa Smith from the University of New Mexico. “The idea certainly took some getting used to.”

    A study by a team of scientists led by John M. Grady of the university studied many different kinds of dinosaurs in their research. They looked at growth rate (比率), body temperature and body size of different kinds of dinosaurs.

    How are warm-blooded animals different from cold-blooded animals? Warm-blooded animals like humans can control their body temperature. They eat a lot, and burn calories (卡路里) quickly. They have a more active lifestyle than cold-blooded animals. While cold-blooded animals such as snakes do not control their body temperature. Instead, they must use sunlight to keep warm, and they move much more slowly. Cold-blooded animals do not need to eat very much. Their bodies slow down in colder temperatures.

    Besides dinosaurs, there are other animals that are not completely warm-blooded or cold-blooded, such as great white sharks.

    Imagine walking through an ancient city, then climbing a gate tower to take in a wonderful view of the city and its more than 600-year-old walls. You can hear the city's heartbeat in the air. This is the Ancient City of Pingyao in Shanxi Province, a place that should definitely be on your travel route if you enjoy history or ancient architecture since its origins can be traced back to more than 2,700 years ago.

    Located in the center of Shanxi Province, Pingyao is the hometown of Jin merchants, a group of merchants who actively dominated (支配) a booming commodity market throughout China for more than 500 years, especially during the Ming and Qing dynasties. After the founding of the People's Republic of China in 1949, the city's agriculture and manufacturing industries developed rapidly. Following China's reform and opening-up in the 1980s, Pingyao struggled with the transition from a managed economy to the current market-oriented economy. During this time, the city government sought out new ways to break through this economic bottleneck.

    Finally in the winter of 1997, opportunity came knocking. Through the efforts of the city government, Pingyao earned its place on the UNESCO World Heritage list, which caused the entire world to take notice of the city.

    Since the city's fame has risen, locals in Pingyao have deepened their understanding of the conservation efforts preserving the historical relics in their hometown. Meanwhile the city administration has continued to upgrade itself through a strategy that follows the pillars of “conservation, entrepreneurship, development and protection.”

    Currently, the city is focused on establishing a sustainable industry that will enable it to continue to grow while also protecting its relics and introducing them to the world.

    Today, I had the good fortune to join the students from East Silver Spring Elementary School in Maryland as they walked and biked to school in celebration of International Walk to School Day. I want to thank Principal Morrow and the entire ESS community for welcoming me so enthusiastically.

    Walk to School Day is a great opportunity for me to spend time with parents, kids, and teachers and to present our Safe Routes to School program and the First Lady Michelle Obama's Let's Move initiative（倡议）.

    As a father, grandfather and former schoolteacher, I know how important it is that we provide students with safe choice to get to school while promoting exercise and healthy lifestyles. That's why I've embraced the Safe Routes to School program so wholeheartedly since I became Secretary of Transportation.

    You know, we're looking at an increasingly sedentary（久坐的）generation of children. One out of every three kids in America is now overweight. And I admire the First Lady's effort to end this within a generation. Safe Routes to School is a natural partner for Let's Move. For more than 10 years, Safe Routes to School has been making it easier for students to walk and bike from home to school. And ESS, where I walked today, is one of the earliest schools to participate.

    We know this program has been enormously effective because of the steady increase in the number of kids walking or biking to school. And as we made our way down the street this morning I was reminded yet again of this program's extraordinary work.

    Look, walking and biking to school is good for students' health. It's good for the environment. And it's good for the entire community's quality of life.

Everybody wins when kids take Safe Routes to School.

    Some people will do just about anything to save money．And I am one of them．Take my family's last vacation．It was my six­year­old son's winter break from school, and we were heading home from Fort Lauderdale after a week long trip．The flight was overbooked, and Delta, the airline, offered us $400 per person in credits to give up our seats and leave the next day．I had meetings in New York, so I had to get back．But that didn't mean my husband and my son couldn't stay．I took my nine­month­old and took off for home．

    The next day, my husband and son were offered more credits to take an even later flight．Yes, I encouraged — okay, ordered — them to wait it out at the airport, to “earn” more Delta Dollars．Our total take: $1,600．Not bad, huh?

    Now some people may think I'm a bad mother and not such a great wife either．But as a big­time bargain hunter, I know the value of a dollar．And these days, a good deal is something few of us can afford to pass up．

    I've made a living looking for the best deals and exposing（揭露）the worst tricks．I have been the consumer reporter of NBC's Today show for over a decade．I have written a couple of books including one titled Tricks of the Trade: A Consumer Survival Guide．And I really do what I believe in．

    I tell you this because there is no shame in getting your money's worth．I'm also tightfisted when it comes to shoes, clothes for my children, and expensive restaurants．But I wouldn't hesitate to spend on a good haircut．It keeps its shape longer, and it's the first thing people notice．And I will also spend on a classic piece of furniture．Quality lasts．

    While faking and fierce looks are among animals great defenses, many species know that everyone runs from a big stink (臭气) too.

    Vulture (秃鸳)

    Vultures, are street sweepers that feast on the rotting flesh of dead animals, which benefits us by ridding our highways and landscapes of animal bodies and the bacteria they might carry. When vultures feel threatened they vomit, and the smell of vomited-on dead bodies puts of most predators. Throwing up allows the vulture to fly away more quickly-and the vomit can hurt the aggressor's eyes and face.

    Opossum (负鼠)

    In some ways opossums have it easy. In order to become "dead", they don't have to fax anyone a death certificate. They just lie there with their tongues hanging out with the smell of dead flesh, sometimes for hours, effectively convincing potential predators they can find a much fresher meal elsewhere. Even if they keep getting attacked, they won't move any more than a human statue until the threat has passed.

    Hoatzin (磨雉)

    Hold your nose and meet the hoatzin, a bird of distinctions, not the least of which is that it smells like fresh cow shit. The animal mostly eats leaves and it's the only bird known to digest by fermentation, like a cow. This process is what causes its smell and has earned it the nickname the "stink bird

    Millipedes (千足虫)

    Millipedes are tricky. For starters they look wormy. Their name is deceptive, too: Their legs number about 750. Their major defense is to curl up into a ball. They, though, also release a harm eyes, and leave a horrible smell on their attackers.

    Sea Hare (海兔)

    The graceful sea hare is plain in taste in the first place, so it's not the most popular dish in the seafood chain. Nonetheless this type of sea creature has a pretty creative smell-related defense that is almost the opposite of its smelly companions on this list. The sea hare gives out a slimy, purple ink, the substance which makes food less palatable to predators.

    Researchers using lobsters (2-f) as model predators found that the sea blocks the lobsters receptive mechanism. In other words, the sea hare gives its attacker the equivalent of a stuffy nose so they don't know how appealing it is.