Check out some fun weekend activities from our friends at Arizona Parenting.

    Walk in the Wild: Walk or run for wildlife at the Phoenix Zoo's Walk in the Wild 2016. Put on your favorite animal dress and take part in the one mile or 5K,enjoying the sights and sounds of the Zoo. Walk in the Wild includes a morning full of unique activities you won't find at any other valley walk, including all-day zoo admission and a lakeside after-party. Register online. 6-10 am. Phoenix Zoo, 455 North Galvin Parkway, Phoenix. 602-286-3800.

    Free Museum Day: It is hosted by Sesame Street and HBO at the Children's Museum of Phoenix. Kids can participate in activities, enjoy a performance by the Sesame Street Muppets and get to join the Everyday Heroes Club. An act of kindness is all it takes to become a member. Performances and activities will take place at 10:30—11:30 am and 1:30—2:30 pm.9 am—4 pm. Children's Museum of Phoenix, 215 N. 7th street, Phoenix. 602-253-0501.

    Sunday A'Fair: Sunday A'Fair features free outdoor concerts in Scottsdale Civic Center Park by top Arizona musicians, along with an arts-and-crafts market, fun activities for children and families, guided tours of the sculptures in the park and free admission to Scottsdale Museum of Contemporary Art (SMoCA). Guests are invited to bring blankets, lawn chairs or picnic baskets, and enjoy a relaxing afternoon of great entertainment. Delicious foods, snacks, beer, wine and soft drinks are also available for purchase.12-4 pm. Scottsdale Center for the Performing Arts, 7380 E. 2^nd St., Scottsdale. 480-994-ARTS (2787).

    To prevent the deserts coming near, China has planted billions of trees—to replace destroyed forests and as barriers against the sand. This isn't a cure, though, say experts, as thirsty trees can make the problem worse by taking in groundwater.

    “Planting tress is one way, but it isn't that simple. It doesn't solve the basic issue of water resources,” says Wu Bo, a professor. “We need to calculate how much water the trees will absorb, or else it could have a negative effect.”

    Villagers in Zhengxin have taken on this challenge, with limited success. When the irrigation channels began to run dry, Lu Xianglin switched from wheat to cotton on his land. He also planted trees to protect his fields from sandstorms. He says he still gets good yields（产量） using flood irrigation and earns a good income for his family.

    Other farmers haven't stuck it out（坚持到底）: about one in three have left Zhengxin in the past 10 years after their wheat crops died. Young people who can find jobs in the towns rarely return.

    Last week, Mr Lu joined the other men in his village on a government-arranged trip to see the land that has been set aside for their relocation, nearly 40 miles to the south. The next day, he was back, shaking his head at the plan. The idea of uprooting his family troubles him, as does the idea of giving up the land that fed his forefathers. He prefers to stay and keep up the fight.

    “With enough water, this problem can be solved,” Lu says. “We can plant trees and grass, and they will grow bigger. That will stop the desert.”

    Experts say that farmers could switch to drip irrigation （滴灌）to lessen their water intake for growing crops. Elsewhere in the region, farmers have built brick greenhouses as part of a plan to grow vegetables using less water. Roadside signs urge farmers to “Save Water, Protect the Environment”.

    Facebook is an Internet-based social network site that lets people get in touch with family and friends and reach out to people with common interests around the world, all through computer. It is very popular, with more than 900 million users. If Facebook were a country, it would have about three times the population of the United States.

    Documents filed with US. financial regulators say Facebook has hundreds of millions of active users who send billions of messages each day and upload 250 million photographs on their personal pages. Facebook users have registered 100 billion “friends.”

    On Facebook, “Friending” someone means you add the person to your list of people you can communicate with directly, which often allows the person to see more information about you than you share with the general public.

    Facebook was started by Mark Zuckerberg and other students at Harvard University in 2004, and has grown at an amazingly fast pace.

    Facebook makes money when advertisers pay to get access to hundreds of millions of Facebook users. Advertisers can often direct their messages to the people most interested in their products because Facebook computers keep track of information that users place on their pages. For example, a person interested in diving, planning a wedding, looking for work, or suffering from diabetes(糖尿病) may see advertisements related to those topics.

    Facebook has become so much a part of the culture of the United States and other nations that it has been the subject of a Hollywood movie. It is a key marketing tool for many businesses, and its users' content has been used as evidence in some divorce or criminal cases.

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    My husband and I had been married nearly twenty-two years when I acquired Stevens-Johnson syndrome, a disorder where my immune system (免疫系统) responded to a virus by producing painful blisters (水疱). Although my long-term evaluation was good, I, who had been so fiercely independent, rapidly became absolutely helpless.

    My husband, Scott, stepped up to the plate, taking care of kids and cooking dinners. He also became my personal caretaker, applying the medicine to all of my blisters because my hands couldn't do the job. Needless to say, I had negative emotions, bouncing from embarrassment to shame caused by total reliance on someone other than myself.

    At one point when I had mentally and physically hit bottoms I remember thinking that Scott must somehow love me more than I could ever love him. With my illness, he had become the stronger one, and I the weaker one. And this disturbed me.

    I recovered from my illness, but I couldn't seem to recover from the thought that I loved my husband less than he loved me. This seeming distinction in our love continued to annoy me for the year following my illness.

    Then recently Scott and I went on a long bike ride. He's an experienced cyclist; I'm quite the green hand. At one point with a strong headwind and sharp pain building in my tired legs, I really thought I couldn't go any further. Seeing me struggle, Scott pulled in front of me and yelled over his shoulder, “Stay close behind me.” As I fell into the draft of his six- foot- three- inch frame and followed his steps, I discovered that my legs quit burning and I was able to catch my breath. My husband was pulling me along again. At this very moment I woke up to what I now believe: during these and other tough times, love has the opportunity to become stronger when one partner learns to lean on the other.

    I pray my husband will always be strong and healthy. But if he should ever become the struggling one, whether on a bike ride or with an illness, I trust I'll be ready to call out to him: Stay close behind me-my turn to pull you along.

    Dodder is an unusual and unwanted plant that attacks other plants. Except for its flowers, the plant looks like spaghetti, a kind of noodles in the shape of long thin pieces that look like string when they are cooked. It's almost leafless, thread-like stems (茎) hang down on top of other plants that dodder needs to stay alive. Dodder does not produce its own food. Instead, it steals food from other plants. It feeds by sucking juices from the plant which is wrapped around, often making its host very weak or even killing it.

    Dodder can find other plants by their smell. When a young dodder plant starts growing, it follows the smell of plants it prefers, like tomato plants, potato plants, or other farm crops. Unlike most plants that usually grow in the direction of light or warmth, a dodder plant will grow in the direction of, for example, tomato smell—if a tomato happens to be growing nearby.

    However, a young dodder plant must find a host plant quickly. It no longer needs its root once it is attached to the host and wrapped around it. If it cannot catch a smell of a potential host within a few days, it will dry up and disappear—even if there is plenty of water around. Once it finds a host, the young dodder plant will attach itself to it and start growing faster. At that point the dodder plant will drop its root.

    Dodder is thus a difficult weed to manage and a real headache for farmers. When it does get out of hand, dodder can greatly reduce a farmer's harvest or even destroy crops completely. Before sowing their produce, especially farmers in warm parts of the world often check to make sure no unwanted dodder seeds have mixed with their crop seeds. This is a good way to stop dodder plants from making their way to a crop field secretly.

Richard Holmes, a British author and academic, is something of a Romantic, famous for biographies of Percy Bysshe Shelley and Samuel Taylor Coleridge. In his last book, "The Age of Wonder", he wrote about science and Romanticism and their common commitment to discovery. In his new book, "Falling Upwards", he combines the two again to tell the stories of Europe's early balloonists (气球飞行者).

Mr Holmes's love of balloons was aroused at a village festival and his enthusiasm is one of the book's many pleasures. He refers to the cheerful tone used in many first-hand ballooning stories, and applies it in this second-hand account. He describes men and women wrapped up in fur coats under their hydrogen-filled balloons, enjoying cold chicken and champagne and looking back to earth to see mankind "for what it really is."

Mr Holmes makes much of the strange side of ballooning, but the book is at its best when examining its more serious applications. In the American civil war, for example, both North and South put observers in balloons to spy on enemy movements. And during the Prussian attack on Paris in 1870-71， balloonists managed to fly out of the city to communicate with the French government in exile (流亡) in Tours.

"Falling Upwards" contains much of the historian's writing characteristics, such as footnotes and bibliography (文献书目), but its epilogue (后记) refers modestly to what has gone before as "a series of true balloon stories". It does touch on the more technical aspects of ballooning, and says little about the French Montgolfier brothers who are credited as its inventors. That though seems a small price to pay for such a spirited work. Mr Holmes's tale ends at the start of the 20th century when the business of flight was being handed over to the airship and the airplane.