Nowadays people are putting our water supply in danger, because they use too much water or throw rubbish into the river. You may wonder how paving(铺砌) a road can lead to less usable fresh water. A major part of thewaterweuse every day is groundwater. Groundwater does not come from lakes or rivers. It comes from underground. The more roads and parking lots we pave，the less water can flow into the ground to become groundwater.

    Human activity is not responsible for all water shortages(短缺). Drier climates are of course more likely to have droughts(干旱) than areas with morerainfall，but in any case, good management can help to make sure there is enough water to meet our basic needs.

    Thinking about the way we use water every day can make a big difference，too. In the United States，a family of four can use 1.5 tons of water a day! This shows how much we depend on water to live，but there's a lot we can do to lower the number.

    You can take steps to save water in your home. To start with，use the same glass for your drinking water all day. Wash it only once a day. Run your dishwasher (洗碗机)only when it is full. Help your parents fix any leaks in your home. You can even help to keep our water supply clean by recycling batteries instead of throwing them away.

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For some people, music is no fun at all. About four percent of the population is what scientists call "amusic." People who are amusic are born without the ability to recognize or reproduce musical notes (音调). Amusic people often cannot tell the difference between two songs. Amusics can only hear the difference between two notes if they are very far apart on the musical scale.

As a result, songs sound like noise to an amusic. Many amusics compare the sound of music to pieces of metal hitting each other. Life can be hard for amusics. Their inability to enjoy music set them apart from others. It can be difficult for other people to identify with their condition. In fact, most people cannot begin to grasp what it feels like to be amusic. Just going to a restaurant or a shopping mall can be uncomfortable or even painful. That is why many amusics intentionally stay away from places where there is music. However, this can result in withdrawal and social isolation. "I used to hate parties," says Margaret, a seventy-year-old woman who only recently discovered that she was amusic. By studying people like Margaret, scientists are finally learning how to identify this unusual condition.

Scientists say that the brains of amusics are different from the brains of people who can appreciate music. The difference is complex, and it doesn't involve defective hearing. Amusics can understand other nonmusical sounds well. They also have no problems understanding ordinary speech. Scientists compare amusics to people who just can't see certain colors.

Many amusics are happy when their condition is finally diagnosed (诊断). For years, Margaret felt embarrassed about her problem with music. Now she knows that she is not alone. There is a name for her condition. That makes it easier for her to explain. "When people invite me to a concert, I just say, ‘No thanks, I'm amusic,'" says Margaret. "I just wish I had learned to say that when I was seventeen and not seventy." (335 words)

    Dubai(迪拜)is one of the economically richest places in the world. With its numerous malls, hotels, and beautiful beaches, Dubai has always been a popular holiday destination. This city was visited by around 5 million tourists each year. The government wanted to increase this number to 15 million. However, Dubai has only 45 miles of coastline, which is nowhere enough for so many people. To solve this problem, an island that looked like a palm tree was built in 2006, and named the Palm Jumeirah.

    The plan for the island was extraordinary. It was to host several hotels, shopping malls, restaurants, and homes. Although the initial plan was to build the island from concrete(水泥), a decision was taken to create it from sand and gravel(砾石), so as to give it a natural look.

    To make sure that this project was a success, the best engineers from across the world were employed. Engineers from Holland formed the majority in this group. To begin with, the engineers calculated the strength of storms at sea, and also the expected amount of rise in water levels due to global warming. And then they found that, the proposed location for the island was neither very wide nor deep.

    One of the difficulties the engineers came across was to put sand on the sea bed to create the breakwater(防浪堤).Finding the right sand for the project was also a daunting task, as the sand from Dubai's deserts was too fine. Instead, sand from the sea was used, as it was coarser(粗糙). Once the breakwater was built, construction of the island began.

    The Palm Island are really impressive in terms of engineering. However, these projects are so large that they may have changed the ecology of the region. Also, an immense amount of money and resources go into maintaining the islands, which is a major concern at the moment. Only time will tell if building the Palm Islands was actually a good decision.

    Do you often dream at night? How do you feel when you dream? Is it useful to our health? “Dreams may be more important than sleep, and we all need to dream,” some scientists say.

    Dreams take up about one quarter of our sleeping time. People have several dreams each night. Dreams are like short films. They are usually in colour. Some dreams are like old films. They come to us over and over again. That may be because the dreamer is worrying about something. Dreaming may be a way of trying to find an answer. Some people get new ideas about their work from dreams. They may have been thinking about their work all day. These thoughts can carry over into dreams.

    Sometimes we wake up with a good feeling from a dream. But often we can't remember the dream. Dreams can disappear quickly from memory.

    Too much dreaming can be harmful. The more we sleep, the longer we dream. The mind is at work when we dream. That is why we may have a long sleep and still wake up tired.

    The world's insects are going down the path of extinction, threatening a "catastrophic collapse of nature's ecosystems", according to the first global scientific review. More than 40％of insect species are declining and third are endangered, the analysis found. The rate of extinction is eight times faster than that of mammals, birds and reptiles.

    "It should be of huge concern to all of us, for insects are at the heart of every food web. They pollinate (授粉) the large majority of plant species, keep the soil healthy, recycle nutrients, control pests, and much more. Love them or 1oathe them, we humans cannot survive without insects, "said Prof Dave Goulson at the University of Sussex in the UK.

    The analysis, published in the journal Biological Conservation, says intensive (集约型) agriculture is the main driver of the declines, particularly the heavy use of pesticides. Urbanisation and climate change are also significant factors.

    "If insect species losses cannot be stopped, this will have catastrophic consequences for both the planet's ecosystems and for the survival of mankind. It is very rapid. In 10 years you will have a quarter less, in 50 years only half left and in 100 years you will have none," said review author Francisco Sánchez-Bayo, at the University of Sydney, Australia.

    One of the biggest impacts of insect loss is on many birds, reptiles, amphibians and fish that eat insects. "If this food source is taken away, all these animals starve to death," he said. Such effects have already been seen in Puerto Rico, where a recent study revealed a 98％fall in ground insects over 35 years.

    Matt Shardlow, at the conservation charity Buglife, said: "It is thoughtful to see this evidence that shows the pitiful state of the world's insect populations. It is increasingly obvious that the planet's ecology is breaking and there is a need for a strong and global effort to prevent and change these terrible trends."