All chordates. a notochord is present at some point in all chordates but sometimes is lost or becomes another structure, like vertebrae
Also idk what “Tregon” so hopefully that didn’t stray from my answer being right
        
             
        
        
        
Explanation:
The flow of the river is dependent upon the position along the stream in terms of the gradient. Near the top of a high gradient, the flow will be less than that near the bottom. Likewise, the steeper the river's gradient, the faster the flow of water (due to the pull of water down the gradient by gravity).
 
        
             
        
        
        
<span>Peloponnesus is the answer to the question</span>
        
             
        
        
        
Answer:
 <em>hope</em><em> </em><em>it</em><em> </em><em>helps</em><em> </em><em>you</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em><em>.</em>