Answer:
Earth:
Our home planet Earth is a rocky, terrestrial planet. It has a solid and active surface with mountains, valleys, canyons, plains and so much more. Earth is special because it is an ocean planet. ... Earth's atmosphere is made mostly of nitrogen and has plenty of oxygen for us to breathe.
living world:
The simplest forms of life consist of one cell. All other living things are composed of a number of tiny living cells, grouped in definite patterns to form whole bodies. A unicellular organism consists of only one tiny cell, in which all living processes take place.
