1) primitive earth: the earth originated from the primitive solar nebula about 4.6 billion years ago. The matter in the nebula disk gradually evolved into the primitive earth through collision and accretion.

(2) Formation of the core, mantle and shell: the temperature of the earth is gradually decreasing, and the internal materials are differentiated. Dense matter gradually gathers in the center of the earth, forming the core; Materials with lower density gather upward to form mantle and crust.

(3) Atmosphere: Large-scale volcanic eruption released gases such as water vapor and carbon dioxide, which constituted the primitive atmosphere.

(4) Hydrosphere: As the surface temperature drops, gaseous water condenses and falls to the ground through rainfall, forming a hydrosphere composed of rivers, lakes and oceans.

(5) The beginning of life: The earliest biological fossils found on the earth were about 3.85 billion years ago.

The History of Earth's Growth is a book published by Renmin University of China Press in 2006. The writer is the editor of CCTV Lecture Room. This book includes the origin of human beings, the language and consciousness of animals, the return of wild animals to nature, the land of dinosaurs, cats on the earth, heavy rain and so on.

The earth is the third planet from the sun and the only celestial body known to breed and support life. About 29.2% of the earth's surface is land composed of continents and islands. The remaining 70.8% is covered by water, most of which are covered by saline water such as oceans and bays, and some are covered by fresh water such as lakes and rivers.