Exercise 1
Diamonds are very expensive for several reasons. First, they are difficult to find. They are only found in a few
places in the world. Second, they are useful. People use diamonds to cut other stones. Third, diamonds do not
change. They stay the same for millions of years. And finally, they are very beautiful.
Exercise 2
There are many different kinds of pollution. One kind is air pollution. This usually is a problem over cities.
Water pollution is another problem. It is found in rivers, lakes and oceans. Also, pollution of the earth is
sometimes a problem near farms. And finally, there is even noise pollution, especially in crowded cities.