____-generation computers used vacuum tubes, cylindrical tubes that controlled the flow of electrons.?

In the constructor of the array implementation of the stack, top is not set to 0 because:

A. it shouldn’t be set to anything until we start pushing elements B. that would mean there is one element already in the stack C. it makes much more sense to set it to 1 D. top is always set to the value of the top element of the stack

With a(n) ____________________, users create a computerized database; add, modify, and delete data in the database; sort and retrieve data from the database; and create forms and reports from the data in the database.

Fill in the blank(s) with the appropriate word(s).