In a model summarizing cellular respiration, which of the following must be represented as raw materials, or the reactants of the process? A. glucose and carbon dioxide
B. glucose and oxygen
C. carbon dioxide and oxygen
D. oxygen and lactic acid

B because you need glucose (energy) and oxygen for metabolic activities in the body to occur such as the digestion of food.

The answer is atmosphere. there are four spheres of the earth: 1. geosphere (from greek word 'geo' = ground), 2. hydrosphere (from greek word 'hydro' = water), 3. biosphere (from greek word 'bio' = life), and 4. atmosphere (from greek word 'atmo' = air). a magnetosphere is a region of space around astronomical objects controlled by the magnetic field of that object. through the process of elimination, since lightning is present in the air, it can be found in the atmosphere.