资料题：Full professors gel a lower avenge income than ruck divers, because（　）。

Large companies need a way to reach the savings of the public.The same problem, on a smaller scale, faces practically every company trying to develop new products and create new jobs.There can be little prospect of raising the money needed from friends and people we know, and while banks may agree to provide short - term loans, they are generally unwilling to provide money on a permanent basis for long term projects.So companies tum to the public, inviting people to lend them money, or take a share in the business in exchange for a share in future profits.They do this by issuing stocks and shares through the stock exchange.By doing so they can put into use the savings o{ individuals and institutions.When the saver wants to have his money back, he does not have to go to the company which has borrowed his money.Instead, he sells his shares through a stockbroker(证券经纪人) to some other saver who is seeking to invest his money.Many of the services needed both by industry, and by each of us are provided by the Government.Without hospital, roads, electricity, telephone, railways ,etc., the county could not function.All these require continuous spending on new equipment if they are to server us properly, requiring more money than is raised through taxes alone.The Government and industries therefore frequently need to borrow money to finance major capital spending, and they, too, go to the stock exchange.There is hardly a man or woman in the county whose job or whose standard of living doesnot depend on the ability of his or her employer to raise money to finance new development.Inone way or another, this new money must come from the savings of the country.The stock exchange exits to provide a channel through which these savings can reach those who need money.