If cars damage the environment by causing an excess of contaminants, then how do cars damage the environment?

Answer choices:
- Battery useage
 - exposure to the sun
 - Emitting an excess of contaminants
 - they travel great distances
 - Using too much gas
 - Causing accidents
 - depress neuronal excitability
 - within and around

 

   Emitting an excess of contaminants       