Why is it bad if sharks didn't exist?

It would be bad because sharks eat fish etc, and if sharks did not exist, fish ( etc ) would be overpopulating.

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.

The short-term effect of tar on the body is increased blood pressure.