• Approximately 70 percent of the Earth's surface is covered by water.
• Oceans: the Pacific Ocean, the Atlantic Ocean, and the Indian Ocean.
• Oceans divide the land mass of planet Earth into tectonic continents.
• Tectonic continents: Eurasia, Africa, North and South America, Australia, and Antarctica.
• Tectonic continents can be divided into geographic continents.
• Geographic continents: Europe, Asia, Africa, South America, North America, Australia, and Antarctica.
• Continents are separated from each other by mountain ranges, inland seas and necks of land.
• Key words: oceans, continents.