Red squirrels used to be a common sight in British forests and countryside. But there are fewer than 140,000 red squirrels left now and most of them are in Scotland. However, grey squirrels (introduced from North America) are now so common that many people dislike them. They can be legally（合法的）trapped and destroyed.

   On first sight, the two types of squirrel are similar. They both have a long tail, which helps the squirrel to balance when jumping from tree to tree, and the same large eyes, small ears and powerful back legs. However, the grey squirrel has a clear physical advantage over the red. The red squirrel has a head-and-body length of 19 to 23 centimeters, a tail length of 15 to 20 centimeters and a body weight of 250 to 340 grams. Compared to this, the grey squirrel is a larger animal. The head and body measures between 23 and 30 centimeters long and the tail is between 19 and 25 centimeters long. Adult grey squirrels are heavier, weighing between 400 and 600 grams. This size allows them to store more fat and helps them to survive a hard winter, which would be fatal（致命的）to their  smaller cousins .

So why are red squirrels losing out in competition with grey squirrels? Size is one factor, but there are others. Red squirrels live high up in trees, while grey squirrels spend more of their time on the ground. This means any loss of forests greatly influences the red squirrel population. Another reason for the grey squirrel's success is its ability to use food provided by people. Like the fox, the grey squirrel can survive in towns and cities. The other problem for the red squirrel is disease. Both squirrels carry a certain virus. While this doesn't seem to attack grey squirrels, it is fatal to red squirrels.

     Life today has brought new problems. One of the biggest is pollution. Noise pollution makes us talk more loudly and become angry more easily. Water pollution makes our rivers and lakes very dirty. Air pollution is the most serious kind of pollution. Both water pollution and air pollution are not only dangerous to our health, but also dangerous to animals and plants.

     Many countries are making new laws to fight pollution. Factories must now clean their water before they throw it away. They can not let out dirty smoke into the air, either. More and more cars are now using a new kind of fuel(燃料) which does not pollute the air.

     Laws are not enough. We must all help. We can use paper bags, not plastic ones. We can keep old cans and plant flowers in them. Everybody must help to fight pollution because we can keep our country clean.

Information Card

    When Paul was a boy growing up in Utah, he happened to live near a copper smelter, and the chemicals that poured out had made a wasteland out of what used to be a beautiful forest. One day a young visitor looked at this wasteland and called it an awful area. Paul knocked him down. From then on, something happened inside him.

    Years later, Paul was back in the area, and he went to the smelter office. He asked if they had any plans or if they would let him try to bring the trees back. The answer from that big industry was "No".

    Paul then went to college to study the science of plants. He told the teacher about his plans. Unfortunately his teacher says, "It will be a waste of your time to try to do it." Everyone knew that, he was told. Even if he was knowledgeable as he had expected, he wouldn't get his idea accepted.

    Paul later got married and had some kids. But this dream would not die. And then one night he did what he could with what he had. Under the cover of darkness, he went to secretly into the wasteland and started planting.

Every week, he made his secret journey into the wasteland and planted trees and grass. For fifteen years he did this against the common sense. Slowly rabbits appeared. Later the company actually hired Paul to do what he was already doing.

    Now the place is covered with fourteen thousand acres of trees and grass and bushes, and Paul has received almost every environmental award Utah has. It took him so many years until his hair turned white, but he managed to keep that impossible promise he made to himself as a child.

Just In Time

    "Come on, Sasha," my father shouted. "Put the book down and get your clarinet(竖笛). We have to leave now if you don't want to miss the class."

    A clarinet class? I thought to myself. {#blank#}1{#/blank#}. Yes, I would like to miss the class. "Coming"{#blank#}2{#/blank#}. I got out of the bed and picked up my clarinet and rushed to the car.

    My dad started the engine and we drove off. "Hope you have a wonderful class," my dad said. "In my dream," I spoke very quietly. "Not again," my dad said angrily.

    I look out of the window{#blank#}3{#/blank#}. "Car traffic", I said under my breath with a big smile. This is my lucky day because I am going to miss the class.

    While we were waiting for the cars to start driving again, I was sitting in my car seat, singing a song. {#blank#}4{#/blank#}. What's important is that I was going to miss the class. "Great! Ten minutes passed," I said excitedly. My dad looked at me angrily. The car started to move.

    "Finally," my dad took a deep breath. We got there and I had only missed a few minutes of the class.{#blank#}5{#/blank#}.

    "Just in time, Sasha. I was thinking you might be getting worried that you were going to miss the class," my teacher made a joke on me –knowing well that I hate the clarinet class！