Many children first learn the value of money by receiving an allowance. The purpose is to let children learn from experience at an age when financial mistakes are not very costly.

    The amount of money that parents give to their children to spend as they wish differs from family to family. Timing is another consideration. Some children get a weekly allowance. Others get a monthly allowance.

    In any case, parents should make clear what, if anything, the child is expected to pay for with the money.

    At first, young children may spend all of their allowance soon after they receive it. If they do this, they will learn the hard way that spending must be done within a budget. Parents are usually advised not to offer more money until the next allowance. The object is to show young people that a budget demands choices between spending and saving. Older children may be responsible enough to save money for larger costs, like clothing or electronics.

    Allowances give children a chance to experience the things they can do with money. They can share it in the form of gifts or giving to a good cause. They can spend it by buying things they want. Or they can save and maybe even invest (投资) it.

    Saving helps children understand that costly goals require sacrifice: you have to cut costs and plan for the future. Requiring children to save part of their allowance can also open the door to future saving and investing. Many banks offer services to help children and teenagers learn about personal finance. A savings account is an excellent way to learn about the power of compound interest (利息). That may not seem like a lot. But over time it adds up.

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    In its early history, Chicago had floods frequently, especially in the spring, making the streets so muddy that people, horses, and carts got stuck. An old joke that was popular at the time went something like this: A man is stuck up to his waist in a muddy Chicago street. Asked if he needs help, he replies,“No, thanks. I've got a good horse under me.”

    The city planners decided to build an underground drainage(排水) system, but there simply wasn't enough difference between the height of the ground level and the water level. The only two options were to lower the Chicago River or raise the city.

    An engineer named Ellis Chesbrough convinced the city that it had no choice but to build the pipes above ground and then cover them with dirt. This raised the level of the city's streets by as much as 12 feet.

    This of course created a new problem: dirt practically buried the first floors of every building in Chicago. Building owners were faced with a choice: either change the first floors of their buildings into basements, and the second stories into main floors, or hoist the entire bulidings to meet the new street level. Small wood-frame buildings could be lifted fairly easily. But what about large, heavy structures like the Tremont Hotel, which was a six-story brick building?

    That's where George Pullman came in. He had developed some house-moving skills successfully. To lift a big structure like Tremont Hotel, Pullman would place thousands of jackscrews(螺旋千斤顶) beneath the building's foundation. One man was assigned to operate each section of roughly 10 jackscrews. At Pullman's signal each man turned his jackscrew the same amount at the same time, thereby raising the building slowly and evenly. Astonishingly, the Tremont Hotel stayed open during the entire operation, and many of its guests didn't even notice anything was happening.

    Some people like to say that every problem has a solution. But in Chicago's early history, every engineering solution seemed to create a new problem. Now that Chicago's waste water was draining efficiently into the Chicago River, the city's next step was to clean the polluted river.

    The Healthy Habits Survey shows that only about one third of American seniors have correct habits. Here are some findings and expert advice.

    Australia is the smallest continent in the world. It is a little smaller than China. It is on the Southern Hemisphere of the earth. Australia is big, but its population is small. The population of Australia is nearly as large as that of Shanghai.

    Enough laws have been made to fight against pollution. The cities in Australia have little air or water pollution. The sky is blue and the water is clean. You can clearly see fish in the rivers. Plants grow very well.

    Last month we visited Perth, the biggest city in Western Australia, and went to a wild flower exhibition. There we saw large numbers of wild flowers on show, most of which we had never seen before. We had a wonderful time. Perth is famous for its beautiful wild flowers. Every year in spring Perth has a wild flower exhibition. After visiting Perth, we spent a day in the countryside. We sat down and had a rest near a path at the foot of a hill. It was quiet and we enjoyed ourselves very much. When we heard bells ringing at the top of the hills, we looked up, but what we saw made us pick up all our things and run back to our car as quickly as we could. There were about three hundred sheep coming towards us along the path.

    Australia is famous for its sheep and kangaroos. After a short drive from any town, you will find yourself among the white sheep. Sheep, sheep, everywhere you can see sheep.

    Have you ever heard of a great Chilean poet? He was once referred to as the Picasso of poetry. Beloved by Chileans of all classes, he is one of the most widely read and respected poets in history. And this year is the 114th birthday of Pablo Neruda(1904—1973).

    Born with the name Neftali Ricardo Reyes Basolto, he was a tall, shy and lonely boy. He loved to read and started to write poetry when he, was ten. The American poet Walt Whitman, whose framed picture Neruda later kept on his table, became a major influence on his work.

    However, his father did not like the idea of having a poet for a son and tried to discourage him from writing. To cover up the publication of his first poem, he took the pen name Pablo Neruda.

    In 1924 Neruda gained fame with his most widely read work “Twenty Love Poems and a Song of Despair”. Yet his rich experience as a diplomat and exile made him go beyond the theme of love. His work also reflected the political struggle of the left and development of South America. He was awarded the Nobel Prize for Literature in 1971.

    Neruda loved the sea which he saw as creative, destructive and forever moving. He found inspiration in the power and freedom of the waves and the seabirds on the coast. “I need the sea because it teaches me,” he wrote. “I move in the university of the waves.” He loved how the sea forever renewed itself, a renewal echoed（共鸣）in his work.

    A new study suggests some language learning can take place during sleep. Researchers from Switzerland's University of Bern say they discovered people were able to learn new language words during deep levels of sleep.

    Much of the earlier research found that memories made when awake were strengthened during sleep. This supported the idea that information learned while awake is replayed and deeply embedded in the sleeping brain.

    The researchers theorized that, if replay during sleep improves the storage of learned information while awake, the processing and storage of new information should also be possible during sleep.

    They carried out experiments on a group of young German­speaking men and women, which centered on periods of deep sleep called "up­states". They identified these slow­wave peaks as the best moments for sleep­learning.

    The researchers observed individuals in a controlled environment during brief periods of sleep. Brain activity was recorded as pairs of words were played for the study subjects. One word in the pair was a real German word. The other was a made­up foreign word. For later identification purposes, the German words chosen were things clearly larger or smaller than a shoebox.

    Each word pair was played four times, with the order of the words changed each time. The word pairs were played at a rhythm that is similar to actual brain activity during deep sleep. The goal was to create a lasting memory link between the false word and the German word that individuals could identify while awake.

    When the subjects woke, they were presented with the false language words­both by sight and sound. They were then asked to guess whether the false word played during sleep represented an object smaller or larger than a shoebox. Results of the study found that a majority of subjects gave more correct answers about the sleep­learned words than would be expected if they had only guessed at random.

    The researchers said they measured increased signals affecting a part of the brain known as the hippocampus. This brain structure is very important for building relational memory during non­sleep periods. The researchers also said memory was best for word pairs presented during slow­wave peaks during sleep.

    The study suggests that memory formation in sleep appears to be caused by the same brain structures that support vocabulary learning while awake. The researchers say more studies are needed to support their findings. However, the experiments do provide new evidence that memories can be formed and vocabulary learning can take place in both conscious and unconscious states.