Activity 2: Identify what is being asked.   _____________1. Which earth system composed of all set of life forms including their habitat? _____________2. How many percent of water that covers the earth? _____________3. Which subsystem mostly made up of invisible gases that surrounds        the earth? _____________4. How many percent of nitrogen present in the atmosphere? _____________5.What do you call the general term for the scientist who specialized the study of internal structure of the earth? _____________6. What is the largest layer and holds 84% of the volume of the earth? ____________ 7. Which layers of the atmosphere where meteors usually burn up as they approach the planet earth. ____________ 8. How many percent of oxygen present in the atmosphere? ____________ 9. What is the earth sub-system that made up of all the liquid and frozen water on Earth? ____________10. What is the innermost layer of the earth that made up of metal alloy?   ​