4. A person who exercises heavily loses a great deal of water as sweat. To maintain homeostasis, the body must keep the concentration of water in the blood from
dropping too far.
- Describe two ways the body can raise or maintain the concentration of water in the
blood.

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.

Nine months old i think but i’m not that sure