How many continents and oceans does the world have?Can you point them out?
    The earth is a very special planet, and it faces a big problem. In the year 2010, the world's population was over 7 billion in total. It is increasing very quickly. By 2025, the world may have about 8 billion people. And by 2050,the world's population may reach 9 billion.
    There is another problem. People can't live everywhere on the earth. We can't live in water,and only about one third of our planet is land. But parts of this land are very dry. These dry places are called deserts. Some areas have very high mountains. Others have a lot of snow and ice. It is not easy to live in those places.
    There are seven continents: Asia, Africa, Australia, Antarctica, Europe, North America and South America. Antarctica is covered with snow and ice all year round. Luckily, people can live on the other six continents. On these continents, there are green forests, fresh water and rich lands.
    Oceans cover two thirds of the earth's surface. The earth has only one big ocean, but we use these names for its different parts:the Pacific Ocean, the Indian Ocean, the Atlantic Ocean and the Arctic Ocean. The Pacific Ocean is the largest one.
    The earth is our home now, and it will be our home in the future. It must be treated well for our children and for our children's children, too!