单项选择题
Questions refer to the following graph.
Assume that in 1990 there were 3,000,000 fourth-graders in the United States. How many fewer of those 3,000,000 students used a computer in school at least once a week in 1994 than in 1990
A．100,000
B．250,000
C．500,000
D．600,000
E． 750,000
B．250,000
C．500,000
D．600,000
E． 750,000