_____ was the first commercially successful computer. a. ENIAC b. Colossus c. Z3 d. UNIVAC _____ -generation computers became possible by the development of integrated circuits. a. Second b. Fourth c. First d. Third _____ computers, such as UNIVAC, can be characterized by their use of vacuum tubes to store individual bits of data. a. First-generation b. Second-generation C. Third-generation d. none of the above _____ is the monetary value of all the goods and services produced by a nation's workforce on an annual basis. a. PLC b. ITC growth c. Productivity d. GDP