— Sorry, I _________________ skating with Tom.

    The weather gets colder. Days get shorter and leaves fall off the trees. Soon, 1 is coming. People can live in warm houses and buy food from the stores. But 2 happens to the animals?

    Animals do many3things to spend winters. Some animals sleep all winter. It is a very deep sleep. They need little or no food, like bears, frogs and snakes. And then they wake up in next4

    Some of them migrate(迁徙). This5they travel to other places where the weather is warmer or they can find food. Many birds migrate in autumn. Some travel in large groups, because the trip can be dangerous. Birds can fly very6 but most birds migrate shorter distances (距离).

    Other animals migrate, too. There are a few mammals (哺乳动物), like whales, travelling to look for 7 to eat in winter. Many8 migrate. They may swim south, or move into deeper and warmer water.

    Many cities around the world today are heavily polluted. Products(产品) are not produced in a "green" way and people haven't realized the importance of buying and using environment-friendly products. These lead to the pollution problem. One result is that millions of tons of waste like glass, paper and plastics is produced. The waste problem is difficult to deal with.

    However, today, more and more people are choosing green and expecting that the products they buy should be safe for the environment. Before they buy a product, they ask questions like these, "Will this soap be bad for the environment?" "Can this metal container be reused or can it only be used once?"

    Over 20,000 people took part in a web survey on buying environment-friendly products. Among them, 8,129 people say that they now consider the environmental safety of a product before they buy it. That is to say, companies must change the way they make and sell their products to make sure that the products are "green".

    A few years ago, it was impossible to find green products in supermarkets, but now there are hundreds. Some supermarket products carry labels(标签) to show that they are green. Some companies have made the clean and safe products their main selling point in advertising.

    The growing need for a safer and cleaner environment is making companies rethink how they do business. The public will no longer accept the old idea of "buy it, use it, throw it away, and forget it". As a result, the companies have to take action.