Arjuna: Mother, how did this world begin?

Mother: Well, there are many different ideas about that. Radhika, why don’t you tell your brother what you learnt about it at school?

Radhika: Scientists believe that the earth was created from a ball of dust and gas. The earth was very hot then. Gradually, it cooled down and hardened.

Arjuna: Wow! What happened after that?

Radhika: The land, the sea and the atmosphere began to form but there was no life on Earth.

Arjuna: Nothing at all?

Radhika: Nothing at all. Life first began in the sea as a bacterium. Plants appeared next on land, followed by

animals.