1. List the elements that are a major constituent of seawater.
     
     
2. List the elements that are a minor constituent of seawater.
     
     
3. List the elements that are dissolved gases in seawater.
     
     
4. Which element is both a gases and a major constituent?
     
     
5. List the major basins.
     
      
        
        
       
6. Which ocean has the longest chain of underwater mountains. 
     
     
7. What are the lines going east to west in the eastern part of the Pacific Ocean?
   
   What causes these?