Answer: They have streamlined bodies with poweful muscles
Explanation: them are some strong boys
 
        
             
        
        
        
Answer: There are 3 major problems with hydrogen as a vehicle fuel, compared to gasoline. 1 - It takes a lot of energy to produce. You have to run a lot of electricity through water to break it down to hydrogen and oxygen. ... It's most useful form is liquid hydrogen, giving far more energy content than as a highly compressed gas.
 
        
             
        
        
        
Answer:
be heritable and be an advantage to offspring
 
        
             
        
        
        
Answer:
We have to evolve or we will just slowly die off.