In the year 2000, the world's population was about six billion. That's 6 000 000 000!
     By 2025, scientists predict the world will have 7.8 billion people. (3). By 2050, there will be 9.1 billion
people.
     People live on land. About one-third of the world is land. There are seven continents: Africa, Asia, Australia, Europe, North America, South America and Antarctica. Antarctica is the world's coldest and the world's driest
continent.
    The world has four main oceans. (4) They are: the Pacific Ocean, the Atlantic Ocean, the Indian Ocean
and the Arctic Ocean. Oceans cover about three-quarters of the earth's surface. 不是所有的陆地都适合人们。(5) Some land is too dry. The land is called desert. Deserts cover one-fifth of the earth's surface.

1. How many people were there in the world in 2000?
    _____________________________________________________________________
2. Which continent do you live in? 
    _____________________________________________________________________
3. 把该句译成汉语。
   ______________________________________________________________________
4. 就划线部分提问，把该句变成特殊疑问句。
   ______________________________________________________________________
5. 把该句译成英语。
   ______________________________________________________________________