Mrs. Smith's children have very good manners because they have been well _________.

A．the U.S. information service sector was equal to 40 percent of the global market share
B．the U.S. information service sector was about one seventh of the global market share
C．computers in the United States is much smaller than that of television
D．computers in the United States had reached about 50 billion by 1992

A．the sharp rise in information processing activities
B．a marked increase in information intensive activities
C．information as an economic resource
D．the establishment of information society