the earth

Formerly people did not know that the earth is round and that it moves around the sun.

Modern travel enables us to go around the world in a few days.

The tropical rainforests, located in a narrow region near the equator, are disappearing so fast that by the year 2000 eighty percent of them may be gone.

There are many countries and many cultures on Earth.

There is no one but knows that the earth is round.