A boy should study hard because a man has to support his family in the future.    

• but: A family belongs to all of the same family, each one of them have the obligation to hold it. Men and women support their families by different ways.   
• because: Even if a man's wife has the ability to support a family, his performance should be excellent, because he is a man.    
  • because: A man is supposed to be the main supporter in a family, who bears the heaviest burden.   
• but: the title of the argument is illogical   
  • because: a man can support a family without studying hard as a boy   
    • because: some successful people did not finish college, for example Bill Gates and Steve Jobs   
  • because: not all men want to have a family   
• but: To support the family, studying hard isn't enough, the man also need to have good personal relation.   
  • but: Study hard to reach the purpose is the most effective method   
• because: Not only boys but also girls should study hard, so as to fit into the society and support himself or herself.   
  • Solution: Girls should also study hard and improve themselves in other aspects for gender equality and obiligation for their future family.