通电的灯泡在发光时，灯丝的温度达到2000℃以上，而连接灯泡的导线却没有明显发热，这主要是因为____，由焦耳定律可知电流通过灯丝产生的热量远大于电流通过导线产生的热量．

    Leaving Hanoi on a fiercely hot summer day,after an hour by air,Luang Prabang gradually appears below our airplane wings.From a few hundred meters above,my first impression of this UNESCO-listed heritage（遗产）is an area of green land and mountains,surrounded by snaking rivers.

    Encircled by mountains,the former royal capital of Luang Prabang is more than just the country's picture-perfect showpiece.

    Travelers will be attracted to Luang Prabang by the city's timeless peacefulness with its shiny Buddhist temples, French colonial architecture and friendly people.

    Tourists visiting Luang Prabang shouldn't miss the chance to see one of the most sacred（神圣的）Lao traditions, tak bat,or the Buddhist almsgiving ritual（仪式）,which dates back to the 14th century.

    As the sun rises in Luang Prabang,hundreds of Buddhist monks depart from their temples to gather their daily offerings,which most commonly are rice,fresh fruit and traditional sweet snacks.The daily alms gathering begins on the main street before spreading to all the side streets.

    Our group of six got out of our comfy beds at 5 am to join other local residents and tourists to offer alms to the monks.We kneeled by the roadside in front of the 3 Nagas Hotel on the main street with big baskets of steamed sticky rice,waiting quietly until monks of all ages passed by to accept our gifts.

    The daily ritual gives you a wonderful opportunity to experience an ancient Lao tradition.However,there are some strict rules if you wish to join the event.

    Firstly,shoulders,chests and legs must be covered in modest clothing as a mark of respect.You should also remain a suitable distance from the monks.Photographs may be taken,but from a distance and never use a camera flash.The ritual has to be performed in silence.Talking to or touching the monks at any time,even when making an offering,is not allowed.

    Another must-do morning activity is to visit the local market,where you can see the generosity that Mother Nature offers this dreamy land.While walking through the morning market,located within a long and narrow hamlet,I was excited to see all kinds of products from the nearby river and jungle: some ill-fated squirrels lying next to fresh bamboo shoots,different kinds of wild mushrooms and vegetables displayed on banana leaves and giant river catfish in baskets.

    Although Luang Prabang is small,there are many things to see here.Active travelers can get up close and personal with Laos' gentle giants at the elephant conservation camp or take in some scenes of riverside life with a cruise or kayak excursion on the rivers.Two waterfalls that are perfect for picnicking in the foothills nearby,and classes are available in traditional crafts.

A. Be a good listener.  B. Care about the details.

C. Strike up a conversation. D. Make time for friendships.

E. Reach out to the newcomers.    F. Avoid causing inconveniences

    Develop Better Relationships with Neighbors

    Good neighbors are a lot like electricity or running water：we don't know how much we depend on them until we don't have them. They make our lives more pleasant and give us a sense of who we wrte, both as an individual and as a member of the community. Here is how to develop your relationships with these very important people in your life.

    ____ Often neighbors don't even know each other's names. But it's okay to be the one to break the ice , even if you've lived next door for years.Most neighbors enjoy making small talk with the folks on the other side of the fence. So as you see them at work in their yards, smile, wave, and say hello. Ask how their kids are (whether they're babies or in college), whether they could use an extra cucumber from your garden, or what they think of the price at the local supermarket.

    ____ These days, the old Welcome Wagon is a thing of the past. But your new neighbors may be feeling lonely and unsure, especially if they're far from home, and might appreciate a friendly face bearing fresh-baked chocolate cakes. If they have kids, tell them where the children in the neighborhood live. Recommend the best places to eat and sleep. Invite them over for coffee or tea when they get settled, give them your number, and point to your house as you say good-bye.

    ____ Return anything that you borrow from a neighbor, such as tools, in good repair and as soon as you've finished with them. Replace anything that belongs to your neighbor that you, your children, or your pets break or soil. Make sure that your car is not blocking their doorway. Such random acts of consideration will have your neighbors talking—and the talk will be good.

    ____ If you value a friendship with your neighbors, spend time with them. What better way to meet your neighbors than to invite them to an informal barbecue, pool party, or holiday open house? Better yet, you might even consider throwing a get-together in their honor. Deliver the invitations in person to everyone who lives on your street and chat with each for five minutes before moving on to the next house. This way, you will get an idea of what your neighbors are like so that you can plan for appropriate food and music.

    ____ In a good relationship, it's really the little things that count. Help to bring in the mail for the elderly neighbor when there is a heavy rain. When your neighbor gorgets to take in his rubbish cans, roll them back into his yard. If you're truly concerned, you'll know when your neighbor needs some cheering up—a bunch of flowers or a helping hand when it's needed. All it takes to develop your relationship with neighbors is the respect for their feelings.

经济学家舒尔茨有一句名言：一旦有了投资机会和有效的鼓励，农民将把黄沙变成黄金。中共从1982年连续三年出现了粮食的超速增长，农民收入也有了大幅增长，终于过上了温饱有余的生活。这主要得益于（    ）