For the Travel section, writers and editors selected special items to profile from a dozen cities.

Brussels:Chocolate

    Nearly half the chocolate consumed in the world is eaten in Europe, and Belgium—with average consumption of 14.99 pounds per person a year—certainly covers its fair share. While Brussels, the country's capital, is home to hundreds of chocolate makers, what makes a visit necessary is the rich heritage of traditional chocolate makers.

Budapest: Paprika (红辣椒)

    The job of preparing Hungarian paprika was once considered too dangerous for mothers to do. A woman who touched her children upon returning from work risked burning them, so only the elderly and unmarried were allowed the delicate task of separating the skin from the flesh. But by the early 20^th century, sweeter varieties and a machine turned paprika into a common feature of all Hungarian cuisine.

Lisbon: Tiles (瓷砖)

    Is there a bluer Country than Portugal? The blue sky and Atlantic Ocean embrace the land. The blue moods of Fado, the dark folk music, form the national soundtrack. And all across Portugal, the typically blue designs of azulejos—ceramic tiles—are spread across churches, castles, palaces, university halls, parks... The result is a beautiful land of Christian saints, Portuguese kings, historical glories, aristocrats at leisure, seascapes and so on.

Madrid: Guitars

    Walking into one of Madrid's storied guitar makers' workshops can feel like stepping into the past. Curly wood shavings, from the palest pine to ebony, fall onto the floor as artisans turn some humble wood into works of art. It's painstaking work—all done by hand—with classical guitar models and the methods of making them changing little over the last century.

    Tim Richter and his wife, Linda, had taught for over 30 years near Buffalo, New York—he in computers, she in special education. “Teaching means everything to us,” Tim would say. In April 1998, he learned he would need a heart operation. It was the kind of news that leads to some serious thinking about life's purpose.

    Not long after the surgery, Tim saw a brochure describing Imagination Library, a program started by Dolly Parton's foundation (基金会) that mailed a book every month to children from birth to age five in the singer's hometown of Sevier, Tennessee. “I thought, maybe Linda and I could do something like this when we retire,” Tim recalls. He placed the brochure on his desk as a “reminder”.

    Five years later, now retired and with that brochure still on the desk, Tim clicked on imagination library com. The program had been opened up to partners who could take advantage of book and postage discounts.

    The quality of the books was of great concern to the Richters. Rather than sign up online, they went to Dollywood for a look see. “We didn't want to give the children rubbish,” says Linda. The books reviewed each year by teachers, literacy specialists and Dollywood board members included classics such as Ezra Jack Keats's The Snowy Day and newer books like Anna Dewdney's Llama Llama series.

    Satisfied, the couple set up the Richter Family Foundation and got to work. Since 2004, they have shipped more than 12,200 books to preschoolers in their area. Megan Williams, a mother of four, is more than appreciative: “This program introduces us to books I've never heard of.”

    The Richters spend about $400 a month sending books to 200 children. “Some people sit there and wait to die,” says Tim. “Others get as busy as they can in the time they have left.”

  Dubai Aquarium & underwater Zoo

    Experience
    You will be surprised at the amazing collection consisting of over 140 species including 300 sharks, rays and the largest collection of sand tiger sharks in the world. Walk along the Rainforest, Rocky Shore and Living Ocean environments at the Underwater Zoo and you will find yourself face to face with dangerous piranha, giant catfish, playful otters, a Humboldt penguin colony and more.
    Options
    Basic Pass: With this basic pass, you'll get access to the Dubai Aquarium and underwater Zoo.
    Explorer Pas: If you're looking to get a little closer to the sea creatures, then this pass is for you. Along with the explorer pass you can also get access to the submersible simulator(潜水模拟器)  & big screen theater and a free ride on the glass-bottom boat.
    VIP Line Buster: This pass includes all the benefits of an explorer pass and a tour guide. And you can get to try your hand at fish feeding!
    Timings
    Sunday--Wednesday: 10:00 am--11:00 pm
    Thursday--Saturday: 10:00 am--12:00 am
    Pro Tip
    You can save a lot by buying a combo ticket(套票). This ticket gives you access to Undersea Zoo and Aquarium Tunnel alongside tickets to the observation deck on the 124th floor of the Burj Khalifa. Your government ID card has to be presented at the entrance.

    Slowly, so slowly that we never even noticed how it happened, our family stopped talking to each other. Our own worlds opened up to us through the computer or the cell phone or the CD player.

    Family Night was born when Mom called us for dinner. Jessica and I came and sat down. Dad loaded his plate and started to rise from the table.

    “Where are you going?” Mom questioned.

    “To the living room. I have some work,” Dad replied as he hurried away. Mom's face got tight, but she said nothing. About two minutes later, my cell phone buzzed. Jessica kept her earphones on during most of the meal. Mom was clearly upset.

    Family Night started the next week. Mom established three rules: no phones, no music, and no leaving the table. Everyone would eat together and play a game together “like a real family.”

    All seemed to be going according to Mom's plan until the first buzz of a cell phone. After dinner, we had been playing the board game for only ten minutes when another cell phone let out a shrill scream. This time the phone belonged to my father.

    “Work's calling. I have to answer,” he whispered as he hurried out of the room.

    Mom sighed, but she forced a smile and encouraged us to continue with the game. We kept playing through every interruption afterwards: the beeping of Jessica's phone, the buzz of another text message from Darnell, the soothing voice announcing the arrival of an e-mail on Dad's computer. When the game was over, Mom released us to our rooms.

    That first Family Night was not a success, but Mom soldiered on. Every Monday evening we silenced our electronics and gathered around the table; and each time, setting aside our technological toys became a little easier. The next two months my father would be taking business trips. We wouldn't be able to have Family Night every Monday.

    To my surprise I realized that I would miss those few hours each week when the house was filled with my family's laughter and conversation. I was also glad to know that when we really wanted to, we could silence the electronic buzz and just be a family again.

    Does the amount of cash in a lost wallet influence how likely a person is to return it? Classical economic theories suggest that the greater the appeal, the less likely we are to be honest—but a new study turns the idea on its head, finding altruism(利他主义), and a powerful hate for viewing oneself as a "thief" outweigh the financial attraction.

    A team of researchers conducted a huge experiment concerning 355 cities in 40 countries. More than 17,000 identical wallets were dropped off at public places, each containing a grocery list, a key, and three business cards in the local language using made-up names and an email address. Some had no money while others contained the equivalent (等值) of $13.45.

    According to the research, people on average returned 40% of wallets with no money in them but 51%with money. It also shows extreme differences between countries. But although rates of people's honesty varied greatly from country to country, one thing remained remarkably constant: wallets with money, as opposed to no money, raised reporting rates.

    In the US, the UK and Poland, they repeated the experiment with even more money: $94.15, which increased reporting rates by an average of 11% compared to the smaller amount. They also found that having a key expanded reporting rates by 9.2%.

    The findings, which run counter to a fundamental principle of classical economics, suggest honesty, altruism and self-image can sometimes be more influential than economic self-interest.

    A purely economic approach to behavior suggests people would keep the wallets with the larger amounts of money due to the increased financial reward, but economics often doesn't account for a person's sense of honesty or self-image, according to behavioral scientists. Altruism also influenced the findings, the researchers say. Since the key is valuable to the owner but not the finder, this pointed toward an altruism concern in addition to the cost of negatively updating one's self image.

Western monarch butterflies(帝王蝶)spend their winters on the central California coast. A few months later, they produce young in the Central Valley and as far north and east as Idaho. But where they go in between remains an open question to biologists. Therefore, a group of biologists call on anyone who spots a monarch north of Santa Barbara this spring to get a quick shot(镜头)and email them the photo with a date and a location.

"Something's going on in early spring," said Cheryl Schultz, a professor at Washington State University Vancouver. "Winter survival isn't the problem in the short term, but they don't know whether the monarchs are not making it producing places, not finding plants to feed themselves along the way," she said.

The Western monarch population stood in the millions in the 1980s. In 2017, an annual count found 200,000 butterflies. In 2018, the number fell to about 30, 000-a figure that held steady last year. The monarchs' decline is part of a large trend among dozens of butterfly species in the West. What exactly caused the decline? Biologists attach it to a variety of reasons. Many chemicals are sprayed on the milkweed(乳草)monarchs will feed on. Climate change also plays a role in challenges facing monarchs. Yet, they're not nearly as threatening as those leading to loss of their living room. Farms used to have rough borders that were grounds for the plants monarchs love and live in. However, newly applied practices pushed crops to the edge of fields.

"Butterflies often have good and bad years. We do think there's potential to turn the situation around." Dr. Schultz said. And she said she saw two reasons for that. First, the population decline seen in 2017 ~ 2018 wasn't repeated last year. And second, she's seen butterfly populations recover before.