In many situations in our life, people take different methods to make up for their carbon footprints, such as paying a bit more when buying flights with certain airlines or planting trees. But have you ever wondered what a carbon footprint is? Where does it come from and how is it measured?

    Originally a footprint was the print made by a foot, just as you might imagine. In the 1960s, due to the development of space travel, the word gradually changed to mean the landing area for a spacecraft. It has continued to gain popularity in the field of technology, with people talking about the footprint of computers, printers and many other such machines. Small footprints are considered to be a positive thing, while large ones are generally bad.

    When the term was associated with carbon dioxide, the meaning changed again. Now, it refers to the amount of carbon dioxide you produce with any action or activity. Today, everyone in the world has a carbon footprint, and it influences the environment directly, for carbon dioxide is known to result in the greenhouse effect. Your carbon footprint is closely related to your lifestyle. Small footprints mean that you're living a simpler, healthier and more sustainable life.

    But what happens if it's big? Well, there are many ways to make up for it, some of which are mentioned in the beginning. To put it more specifically, you can balance the negative effects of your actions by using green fuels, recycling, reforestation(重新造林) and a number of other activities to reduce the emission of carbon dioxide.

    So, before you print out this booklet, think about your carbon footprint and make the right choice.

    Have you noticed the number of plastic bags in your house? I just realised that my cupboards in the kitchen are full of them, and without even realising it, they are taking over my home! Actually, this is just one example of how plastic-this useful material -is almost everywhere in our life. Convenient as it is, however, it's unfortunately not the easiest thing to break down and recycle, causing serious environmental problems.

    Nowadays, most of our plastic waste is buried and left to break down for years. But some of it blows away, blighting the countryside and causing damage to the natural environment and the wildlife. The situation is most severe in our oceans.

Some biologists and marine scientists have claimed that the plastic waste is now impacting most islands in the world as well as the majority of species in the ocean in various ways.

    This highlights the negative effect of the disposable (一次性的) culture. When we throw a plastic item away, it doesn't just disappear. Instead, it goes somewhere and could somehow end in the ocean. Due to its durable nature, it takes a long time to break down and causes great damage to the ocean's ecology. Some recent research also mentions that 90 per cent of all seabirds have swallowed plastic。And what's worse, the plastic item can be broken down into tiny pieces over a long period of time by the wind and the waves. It later becomes the food of the sea creatures at the bottom of the food chain. These creatures are then eaten by the fish that eventually ends in our stomach.

    We could solve this problem by using less plastic. Several countries now charge for using plastic bags, and some products now use natural and recyclable materials. But it still seems unlikely to stop using plastic once and for all, and plastic will continue to be a necessary part in many of the things that we demand.

    So next time you use a plastic bag, take some time to think about the animals on the remote islands as well as in the oceans.

    If you look up at the sky on an autumn day, you might be able to see a V-formation made up of birds. All summer, they have lived in the north, making their nests and raising their young. When winter comes, snow and ice will cover their habitats in the north, so they must migrate south where food is easier to find.

    The Arctic tern, for example, travels 60,000 to 82, 000 kilometres from one polar region to the other, and back again. This may be the longest migration of any animal on Earth. Surprising as it may seem, not all birds migrate. Some don't as they can change their diet to adapt to winter. For most species, however, it is easier to migrate to other habitats where the climate is not as severe.

    One thing about bird migration intrigues the scientists a lot. That is, these birds somehow know exactly where they are heading and how to get there. It is amazing to think about how birds are able to return to the same place every year. Others, however, think that migratory birds follow certain coastlines, mountains and rivers to find the direction. However they do it, these amazing creatures always arrive in the right place at the right time. In the spring, they return to their nesting grounds up north to lay their eggs and care for their young.

    With the issue of environmental damage becoming more severe, it is important for people to protect the estuaries(河口) and wetlands. With so many birds, habitats threatened in the world, we as well as the future generations may never be able to enjoy the beauty of these migrating wonders.

A. These birds, therefore, stay in the same place all year round.

B. They are of great importance to endangered species

C. During migration, some birds will travel great distances, crossing entire continents and oceans.

D. They are flying south where it is warm and rich in food in winter.

E. Birds fly around the world according to the weather year around year.

F. Some scientists believe that birds might use the stars for direction.

G. The birds that migrate south in winter return to different places when the weather is warm.

    In our modern world, when something wears out, we throw it away and buy a new one. The problem is that countries around the world have growing mountains of1because people are throwing out more things than ever before.

    How did we2a throw-away society? First of all, it is now easier to3an object than to spend time and money repairing it. Thanks to modern manufacturing(制造业)and technology, companies are able to produce products quickly and inexpensively. Products are plentiful and4.

    Another cause is our 5of disposable products. Living in a society where efficiency comes first, we are always looking for6to save time and make our lives easier. Companies produce thousands of different kinds of disposable products: paper plates, plastic cups and cameras, to name a few.

    Our appetite for new products also7to the problem. We are8buying new things. Advertisements persuade us that the9is better and that we will be happier with the latest products. The result is that we10useful possessions to make room for new ones.

    All around the world. We can see the11of this throw-away lifestyle. Mountains of rubbish just keep getting bigger. To12the amount of rubbish and protect the environment, more governments are requiring people to recycle materials.13, this is not enough to solve our problem.

    Maybe there is another way out. We need to repair our possessions 14throwing them away. We also need to rethink our attitudes to15. Repairing our possessions and changing our spending habits may be the best way to reduce the amount of rubbish and take care of our environment.