The memory state of each byte of memory is represented by one of these letters R, Y, G, or B. These letters correspond to the colors red, yellow, green, and blue, respectively.

G Here, a and g, we've already got as functions of these easily controlled, conveniently controlled state variables.

But Michael G. Moore, a professor of education at Pennsylvania State University, said programs that combine virtual education and face-to-face instruction could be effective.