You may think that light pollution isn't something extraordinarily important. You may believe that every other type of pollution has a larger impact on the environment that light pollution does. But light pollution is serious.

    Light pollution, or “sky glow”, is the glow you can see at night above cities and towns. Light pollution is a problem that has been accompanying man ever since he started his first fire some 15,000 years ago. Light pollution is the light that comes from streetlights, buildings, parking lots and any other source of light that is reflected or directed into the atmosphere.

    Urban light pollution means that one-fifth of the world's population can no longer see the Milky Way(银河) with the naked eye(肉眼). Many city kids, even if they did look through the orange smog above their heads, would probably see only a handful of stars. We have lost our view of the stars, and we have mucked up our  night-time environment as well. Astronomers are calling for the dark places on Earth to be preserved as national parks.

    Lots of people find the ever-brightening night annoying, and animals that are programmed to prefer the dark may avoid a brightened habitat. Sea turtles can get lost searching for a beach to lay eggs, and their hatchlings(孵化的幼仔)may confuse over-lit beachfront resorts(度假胜地) for the ocean horizon, wasting precious energy needed to find the sea and escape predators(食肉动物). Because their necks aren't yet long enough to see things far away, baby turtles rely on the mirror image of the moon to guide them to the sea, to begin their new life. A car may even hit a particular turtle, which was thinking the light from a nearby city was moonlight reflecting off the ocean waves. Birds that live in and around cities can die because of sky glow, too. The bright lights can blind them, leading to countless collisions with buildings and other tall structures.

    On an individual level, people can help reduce much sky glow by using lighting only when necessary. The stars above us are priceless heritage— for not only for astronomers but for all humans. More of our children should be able to look up at night and see the Milk Way.

    I walked to Mrs. Windsor's house and waited outside. She was working with another student, and I was not supposed to bother them by ringing the bell. I stood against the wall and daydreamed what I'd rather be doing. I had been tutored enough to read, understand, and even write some musical compositions, but I just didn't have a gift for it. Mrs. Windsor had offered to give me the lessons for free, so I felt my duty to try.

    The door opened and Wendy Barton came out. I walked in, sat down on the piano bench and began to sort through my sheet music. Today Mrs. Windsor introduced her niece Pasha to teach me. With a smile, Pasha sat beside me on the piano bench, opened my sheet music to the beginning page and asked me to play. I arranged my fingers on the keys. Then I frowned(皱眉) and concentrated to make the notes on the page match the finger movements. I had to admit I was a rather mechanical (呆板的) pianist.

    After about a page or two, Pasha gently put her hand on top of mine as if to calm my fingers. There was a long pause. "What are you hearing in the music?" I looked at her rather strangely and admitted I didn't know what she meant. "Like a story. Here, let me try and you listen," Pasha advised.

    She closed her eyes and took a deep breath, letting her fingers dance lightly over the keys. Then, she began to play. "See, it begins here beside some kind of river. Hear the water flowing beside you?"

    Her fingers rose and fell gently on the keys. "Now the princess appears and she's picking flowers from the water's edge." A happy piece of music filled the air in time to Pasha's dancing fingers. "Oh, but she slips!" The music changed. "And our princess is being carried off by the fast-flowing stream. Quickly, the princess' horse sees her plight (困境) and races to the river's edge where he swims out to let her catch hold of him. Luckily, they make it to the bank." Pasha said.

    I played many pieces of music that afternoon, finding the stories in the music and learning that sometimes it takes a friend to pull you out of the river onto dry land again.

    When people today talk about a tiny house, they probably mean the trendy living space that's about the size of a shed (棚). But you would have to be five inches tall to live in the original tiny houses. Dollhouse(小房子)，which have been around for several centuries, don't offer shelter to real people, but they provide a vivid（生动的） experience of life in times and places both real and imaginary.

    The National Building Museum in Washington, D.C., lets visitors time travel in this tiny world through ―Small Stories: At Home in a Dollhouse,” an exhibit that opened Saturday. Visitors can see twelve dollhouses from the Victoria and Albert Museum in London, England, which contain amazing tiny furnishings. But those people who put together the exhibit also wanted visitors to know the characters inside.

    “It's 300 years of British homes told through their inhabitants (居民),” said Alice Sage, who is in charge of the London museum.

    So as visitors look inside the Tate Baby House, a fancy townhouse from 1760, they can push a button to hear a young woman get a lecture from her mother on the proper way to run a home. In the Killer Cabinet house, a servant named Betsy complains about the problems of city life in the 1830s. “We've got the cat to keep the rats away,” she says.

    That dollhouse was John Killer's gift to his wife and five daughters. The girls were allowed to play with the house, but they probably also learned a few lessons, Sage said.

    “The kitchen of the house would have been the perfect way to teach the girls about the management of a home,” she said, noting the tiny dishes and pots.

    Those who prefer a more modern look won't be disappointed. There are two rooms displaying a white dollhouse from 1935, an apartment house from the 1960s and a brightly colored 21st-century design.

    The end of the exhibit shows how imaginative design sometimes works best in small spaces.

    The Building Museum asked twenty-four artists, designers and architects from across the United States to each create a “dream room” from the past, present or future. Some of these unique small rooms were made using traditional furnishings, others from materials such as clay, insects, 3D-printing, and even peeps marshmallow candies!

    One day, Mr. Smith went to a dinner party. He was wearing very old clothes. He came into the room.But people in the room didn't look at him. They didn't ask him to sit at the table. He wasn't happy. But he said nothing.Mr. Smith went home quickly and put on his best clothes. He went back to the party. Everyone in the room stood up and looked at him. They gave him good food to eat.Mr. Smith took off his coat, and put it on the food and said, "Eat, coat!" The other people were surprised and asked, "What are you doing? Why do you do that?" Mr. Smith answered, "I am asking my coat to eat food. When I wore old clothes, you didn't look at me. You didn't ask me to sit down. Now I am wearing these nice clothes. And you give me good food. Now I see, you give the food to my coat, not to me."

    Fikiri Kiponda's path from accountant to marine (海洋的) conservationist was sparked by a chance encounter.    After securing his dream job, Kiponda decided he wanted more. He wasn't quite sure what he was looking for until he ran across some turtle hatchlings.

    He didn't know it was turtle. Fortunately enough he got the right person to ask and he got motivated. That person was Nkindi, a staff member at the Watamu Conservation project who later invited him to volunteer on the project. He later left his accounting job and fully devoted himself into the world of sea turtles. Now，he runs and spends his time nursing critically endangered sea turtles back to health.

    Sea turtles have been around for nearly 110 million years and are now considered highly endangered. Their preservation rests on activities of conservationists such as Kiponda as these turtles face numerous threats and signs of their extinction in the next 50 years.

    Local fishermen traditionally catch them to supplement their own low catch rates and sell them for their oil. As changes are made to accommodate more hotels for tourists, there is less available beach land for turtle nesting.

    Kiponda's passion has now spread to his community, changing their attitude towards sea life preservation with his “by-catch release programme.”

    Through this program, fishermen are now paid for returning turtles accidentally caught in their fishing nets. The healthy ones are tagged and released into the marine park while he takes care of sick and injured turtles back to health.

    Before the launch of pioneering spirit like this, turtles caught by fishermen were used for their meat and their oil extracted (提炼) for its medicinal properties.

    “Releasing the turtle back into the ocean is a very good feeling, like, you feel like you've done something concrete and I guess everybody would love to do that...so I guess it's unique work.”

    Life is difficult.

    What do you think about life? Maybe most people say that life is difficult. But life is no longer difficult once we truly understand and accept it. Most people do not fully see this truth. Instead, they complain about their problems and difficulties as if life should be easy. It seems to them that their difficulties represent a special kind of suffering especially forced upon (强加于) them or their families, their class, or even their nation.

    What makes life difficult is that the process of facing and solving problems is a painful one. Problems, depending on their nature, cause us sadness or loneliness or regret or anger or fear. These are uncomfortable feelings, often as painful as any kind of physical pain. And since life causes an endless series of problems, life is always difficult and is full of pain as well as joy.

    Yet, it is in this whole process of solving problems that life has its meaning.

    Problems are the serious test that tells success from failure. When we desire to encourage the growth of the human spirit, we encourage the human ability to solve problems, just as in school we set problems for our children to solve. It is through the pain of meeting and working out problems that we learn. As Benjamin Franklin said, "Those things that hurt instruct." It is for this reason that wise people learn not to fear but to welcome the pain of problems.