单选题
The recent boom in technological advances, formation of new businesses, and personal (1) is the third, and most dramatic, such wave (2) by the computer industry in the last twenty-five years. The first wave (3) tangible products—"hardware," as (4) the computer programs that (5) software. In the 1960s and 1970s companies in the Santa Clara Valley, between San Jose and San Francisco, produced silicon memory chips for computers— (6) the name Silicon Valley. Then they produced silicon logic chips, (7) direct a computer's operation. Then many produced computers (8) . The great (9) from the hardware era include those of the Hewlett and Packard families, of Hewlett-Packard, which started (10) money in the presilicon era, with scientific instruments. The Packard Foundation, with (11) of ＄10 billion, recently (12) the Ford Foundation as the nation's third-largest private foundation The (13) hardware company of the 1990s is Intel, (14) Pentium and other processing chips are used in most personal computers (15) the Macintosh. The second (16) of wealth creation involved software—"application" software that people use for work or recreation, like word-processing programs or computer games, and "systems" software used to (17) businesses or, very often, computer networks (18) . The difference between software and hardware provides a classic illustration of (19) economists mean by "increasing returns to scale." Because the cost of producing additional units of software—the "marginal cost"- is extremely low, (20) you become the market leader in a field, your profits grow astronomically.