Amajor reason for 3-level architecture is to

Pp 4.1 design and implement a class called sphere that contains instance data that represents the sphere’s diameter. define the sphere constructor to accept and initialize the diameter and include getter and setter methods for the diameter. include methods that calculate and return the volume and surface area of the sphere (see pp 3.5 for the formulas). include a tostring method that returns a one-line description of the sphere. create a driver class called multisphere, whose main method instantiates and updates several sphere objects.

2. fluorine and chlorine molecules are blamed fora trapping the sun's energyob forming acid rainoc producing smogod destroying ozone molecules

Afiling system in which an intermediary source of reference, such as a file card, must be consulted to locate specific files is called a(n) system. a. shelf filing b. direct filing c. indirect filing d. shingling