21.Which storage medium would you use in each of the following situations: (1) airline reservations system, (2) information on employee benefits and professional conduct, and (3) online answers to customers frequently asked questions (FAQs)? Explain your choices.

23. Comment on the following statement: the useful life of a PC is about two years, therefore, it is not important whether the vendor is still in business in two or three years.

28. Try to count how many hours per week you use a personal computer: at your home, in the PC lab, in the library, or elsewhere. Do you consider yourself computer addicted?