Answer:
Due suitable environment and high productivity.
Explanation:
More fish are supplied by fish farming rather than from traditional because farms are build in order to harvest more fish by providing suitable environment to the fish. In transitional ways, fish are caught in nets from the rivers by local people for theirselves and the extra will sold in the market. In rivers there are less number of fish which does not meet the requirements of people so that's why commercial farming of fish can be done.
 
        
             
        
        
        
Answer:
 look
Explanation:
Flatworms, roundworms, and segmented worms are all invertebrates. Some species of each type of worm are free-living, meaning they are not dependent on another organism.Some are parasitic.
Flatworms belong to phylum Platyhelminthes. They do not have a coelom, respiratory system or a circulatory system.Tapeworms flukes are examples of flatworms.
Roundworms are part of the phylum Nematoda. They are bilaterally symmetrical invertebrates.They have a psuedocoelom. Ascaris lumbricodes is the most common human parasite.
Segmented worms are the most complex animals of these three invertebrates. They are placed in Annelida. Segmented worms have a true coelom, a circulatory system and a digestive system.An earthworm is a segmented worm.
 
        
             
        
        
        
Polar molecules occur when two atoms do not share electrons equally in a covalent bond. While polar molecules have two parts with opposite charges (i.e., positive and negative), nonpolar molecules have no dipole, meaning that there is molecular symmetry, which results in no opposing charges.