Answer:
Start from the bottom and go up. 
 
        
             
        
        
        
The answer is single opening. The gastrovascular cavity varies from the alimentary canal in that only the gastrovascular cavity has only a single opening. In addition, an alimentary canal has two openings and food moves over it unidirectional. The gastrovascular cavity is a construction establish in primitive animal phyla. It is accountable in cooperation with the digestion of food and the transportation of nutrients all over the body.
        
             
        
        
        
Yes they have a similar mode of nutrition also you’re welcomeeee
        
             
        
        
        
Answer:
You just answered yourself buddy
Explanation: