15 15 
why I that awnser is 15
15
        
             
        
        
        
Answer:
B
Explanation:
B is the most likely consequence because of the following facts we are told:
- After apple trees were introduced, some apple maggots began feeding from and laying their eggs on apple trees
- Adult apple maggots will only mate on the type of tree on which they were born.
This provides a geographical isolation (because they are feeding and laying eggs on separate trees) and reproductive isolation (because they will only mate on the type of tree on which they are born).
These two factors increase the chances that apple maggots feeding on apple trees will only encounter those who have mated on the same tree, and continue to mate this way. Over time, the populations (i.e. apple tree vs hawthorn tree) will intermix less and less. This will mean the genetic pool will become distinct, and natural selection will be acting differently (different habitats and different genes), encouraging speciation. 
 
        
                    
             
        
        
        
Hallucinogenic drugs are drugs such as LSD that produce hallucinations for its users. Another word that is used when referring to the drugs is "psychedelic",, which refers to these hallucinations. The word psychedelic refers to the hallucinations that these hallucinogenic drugs give.
Let me know if you have any further questions
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Answer:
c. switching from beef to soy
Explanation:
Switching from beef to soy shall lead to the curbing of lifestyle diseases such as obesity.
At the same time, soy shall provide the nutrients that were needed by the body and could be obtained from beef.
Beef is much expensive compared to beef, thereby, there shall be experienced  low expenditure compared to beef.
Therefore the switching from soy to beef shall be a more sustainable food system.