<span>The geologic time scale is divided into periods, which are then divided into epochs, which are further divided into ages. For example, the time of the dinosaurs lasted 3 periods (Triassic, Jurassic, Cretaceous), each period had 3 epochs (late, early, middle), and each age fit into one of those. Many epochs have more than 1 age associated with them. 
As for the basis for differentiating the eras, I'm not so sure. The only one I can say for sure is the end of the Cretaceous, which is when the dinosaurs suddenly became extinct due to a meteor impact. I think the divisions are based on significant, global-scale events that changed the world.
Sorry its so long but that the answer i think >:) ur welcome
</span>
        
             
        
        
        
Answer:
C, a long absolute refractory period.
Explanation:
Tetanus is not possible in cardiac muscle tissue because cardiac cells have longer action potentials and a very long refractory period compared to other cells. This helps prevent the heart from cramping and seizing up.
 
        
             
        
        
        
Answer:stream Flow or the channel runoff
Explanation:
Explanation:
 
        
             
        
        
        
Evaporation
Explanation:
Evaporation is one change that would cause more water to evaporate from a stream. 
Evaporation is a phase change in which liquid is changed into its gaseous form. 
- When a substance is heated from solid to liquid, it melts. 
- After melting, additional heat causes a phase change that allows for the liquid to change to gases. 
- In the water cycle, the sun provides heat energy that causes surface water in streams to be heated. 
- This leads to evaporation of the surface water into the atmosphere where they can be condensed to form precipitation. 
Learn more: 
Phase change brainly.com/question/10972073
#learnwithBrainly