What types of industries have unearned revenue? Why is unearned revenue consider

What types of industries have unearned revenue? Why is unearned revenue considered a liability? When is the unearned revenue recognized in the financial statements?Why do companies issue bonds? Would you rather buy a bond at a discount or a premium rate? Why? What is the determining factor of whether a bond is sold at a discount face or premium?What is the straight-line method of amortizing discount and premium on bonds payable? Provide an explanation of the process.How would you describe the accounting procedures for notes payable and accounts payable?