The earth was just a cloud of dust before it settled into a solid globe. Then it e  1___loudly with fire and rock, which were in time to p  2  different gases and make the earth¡¯s a____3___. As the earth cooled down, water began to appear on its s  4  . It allowed the earth to dissolve   h___5   gasses and acids into the oceans and seas, w  6    made it possible for life to develop. Millions of years later, small plants multiplied and e  7    the development of early shellfish and fish. Then green plants began to grow on land and were f    8   by land animals such as insects, amphibians, reptiles and dinosaurs. Later the d  9 _____of the dinosaurs made possible the rise of mammals on the earth. Finally human beings appeared and s___10___all over the earth.