At times my mom has been uncomfortable seeing these qualities in me. For example, when I was 12, I went to Puerto Rico all by myself to stay with my grandmother for the summer. My mom was extremely nervous about it. She kept telling me how things were different in Puerto Rico, to always put on sunscreen, not to wander away from my grandmother, and other warnings. She helped me pack and did not leave the airport until she saw my plane take off.

    But despite her worries, she let me go on my own. As I moved into my teens, she continued to give me space to grow and learn even when it might have been difficult for her. When I reached my senior year, I decided to move away for college. Once again I found that I differed from my peers: while many of them wanted to stay close to home, I couldn't wait to be out in the world on my own. While my mom may not have been happy at the thought of me going away, she was supportive and excited for me.

    One big thing I realized during my senior year, as my mom granted me more freedom, was that she actually believes in me and trusts me. That means a lot. Most of my life, and especially when I was little, the main person I tried to impress in my schoolwork or other things was my mother. I knew she expected nothing but the best from me. Sometimes it was hard to live up to her standards; getting a single B on my report card would make me feel bad because I knew she wanted me to have all A's.

    I know that her high standards have helped me stay focused on what's important, like education, and made me who I am. I am thankful for her support and involvement in my life. Most of all I respect her. She is the strongest woman I know and that's why I have turned out so strong and independent.

    With the coming of winter, it's the perfect time to get out of town and escape the seasonal mood（心情）disorder. Here are vacation ideas to adopt now.

    Costa Rica

    Costa Rica, located in the Valle del General, is well-known for its coffee, pineapples and sugar cane plantations as well as its rich forests. What's more, you can enjoy horseback riding, spend afternoons at the spa or tour a nearby wildlife shelter to look out for colorful birds, sloths and other animals.

    Los Cabos, Mexico

    If you love wine, travel to Los Cabos, a beautiful vacation destination at the southern edge of the Baja Peninsula. During your getaway, you can enjoy special wine tastings and dinner cooked by Los Cabos's Michelin-starred chef. There are wild-viewing opportunities, too. From December through May, you can spot whales, manta rays and more wildlife.

    Petit St Vincent, the Grenadines

    This private Caribbean island was spared（使幸免）the anger of hurricanes Irma and Maria. What's more, the whole island is only 115 acres and has 22 cottages（小屋）. Each cottage is located in a quiet place, and you can expect to unplug and recharge phones with no wireless connections, television or telephones in the cottage. Even better, you can spend your days admiring fascinating marine（海洋的）life at the Jean-Michel Cousteau Diving Caribbean center.

    The Exumas, Bahamas

    On Fowl Cay's 50-acre private island, you can enjoy a carefree escape. Days can be spent fishing, boating and diving before wandering along white sands. The resort features large one, two-and three-bedroom houses. Best of all, if you're planning a group getaway or multigenerational trip, you rent the entire island for a unique island escape.

    If you're new to San Francisco, paying the city a visit, or simply looking for a new playground for you and your dog, here are four of the finest dog parks in San Francisco.

    Corona Heights Dog Park

    Often visited by residents from all over the city because of its nearness to the Randall Museum, Corona Heights Dog Park offers pets and owners breathtaking view after a steep hillside climb, and a fenced dog area that allows dogs to let loose without a leash（狗链）. Owners will also enjoy the playground, tennis courts and basketball courts.

    Dolores Dog Park

    The grounds of Dolores Park once served as camps for those who were left homeless by the 1906 earthquake, but now are often visited by crowds of Mission District people. Four-legged friends can also wander about carefree off-leash while making friends with other members of the doggie community.

    Pine Lake Dog Park

    Famous for its place as a rest stop for hundreds of species of birds to fly to and from warmer climates, Pine Lake Park is also prized by city dogs and their owners for their nice hiking paths, picturesque lake suited for swimming, and off-leash area on the park's west end that lets dogs run free.

    Buena Vista Dog Park

    With a history of 146 years, Buena Vista Park is San Francisco's oldest park. Dogs and owners with plus energy will love burning it on this park's steep paths and winding staircases. Dog owners should have good control over their dogs, as it's quite easy for dogs to get separated when going through Buena Vista's many twists and turns.

    America is a mobile society. Friendships between Americans can be close and real, yet disappear soon if situations change. Neither side feels hurt by this. Both may exchange Christmas greetings for a year or two, perhaps a few letters for a while — then no more. If the same two people meet again by chance, even years later, they pick up the friendship. This can be quite difficult for us Chinese to understand, because friendships between us flower more slowly but then may become lifelong feelings, extending (延伸) sometimes deeply into both families.

    Americans are ready to receive us foreigners at their homes, share their holidays, and their home life. They will enjoy welcoming us and be pleased if we accept their hospitality (好客) easily.

    Another difficult point for us Chinese to understand Americans is that although they include us warmly in their personal everyday lives, they don't show their politeness to us if it requires a great deal of time. This is usually the opposite of the practice in our country where we may be generous with our time. Sometimes, we, as hosts, will appear at airports even in the middle of the night to meet a friend. We may take days off to act as guides to our foreign friends. The Americans, however, express their welcome usually at homes, but truly can not manage the time to do a great deal with a visitor outside their daily routine. They will probably expect us to get ourselves from the airport to our own hotel by bus. And they expect that we will phone them from there. Once we arrive at their homes, the welcome will be full, warm and real. We will find ourselves treated hospitably.

    For the Americans, it is often considered friendly to invite a friend to their homes than to go to restaurants, except for purely business matters. So accept their hospitality at home!

    On November 7, Lewis Pugh completed a one-kilometer swim in the freezing waters of King Edward Cove, off South Georgia in Antarctica. He was wearing only his swimming glasses, cap and speedos!

    Pugh is an advocate for our oceans and seas, working to protect these ecosystem with their large diversity of marine life. When asked why he doesn't wear a wetsuit, Lewis says, "I ask world leaders to do everything they can to protect our oceans. Sometimes the steps they need to take are difficult and unpopular. If I'm asking them to be courageous, I must also be. Swimming in a wetsuit would not send the right message."

    It took Pugh about 19 minutes to complete the one-kilometer swim in Antarctica where the water averaged about 1.6 degrees Celsius. He says that his body can only tolerate about 20 minutes in the freezing waters before it starts shutting down. As he swims, his body temperature steadily drops, which in turn causes his muscle control to drop, slowing him down. When he is done with his swim, his support team rushes him to a hot shower and it takes almost an hour for his body temperature to return to normal.

    Doctors and Pugh caution that one must receive months of training to swim in such cold waters. Even expert swimmers who are unused to freezing water can drown within minutes because of the physical shock experienced by the body. Pugh says he trained for six months before this swim.

    This is not the first time that Lewis has swum in dangerous conditions. In 2007, he swam one kilometer in the North Pole to draw attention to the melting Arctic ice due to climate change. In 2015, he swam in the Bay of Whales in Antarctica's Ross Sea as part of his successful campaign to help set up a marine reserve there.

All animals play. Runing, rolling and wrestling with each other is a way for them to have fun, of course. But it also seems to be how they communicate and strengthen bonds with each other.

When a dog comes up to another dog, front legs bowed and his tail high, his buddy knows he wants to play. But new research shows that this play behavior is surprisingly similar when horses and dogs play.

To study interspecies communication, Elisabetta Palagi and her colleagues from the University of Pisa found 20 YouTube videos of dogs and horses playing where their interactions lasted at least 30 seconds. They analyzed the videos, looking for specific pattern of play.

They found that while playing, both dogs and horses often had relaxed, open mouths-which is common playful facial expression in mammals. Some also copied each other's movements, like pretending to bite, playing with an object, or rolling on their backs on the ground. A 2,000-pound horse can play with a relatively tiny dog because the two are able to communicate their intentions.

"It's an important study because it shows how two animals who look and behave so differently can nevertheless manage to negotiate how to play in a way that's comfortable for both," Barbara Smuts, a behavioral ecologist at the University of Michigan, told National Geographic.

It's even more noteworthy given the large size difference between horses and dogs. The dog is vulnerable (易受伤的) to injury by the horse, and the horse has a deeply rooted tendency to fear animals that look like wolves."

Next up, the researchers write, is exploring the development and shaping of interspecies communication that “can be at the basis of a universal language of play".