EFFECTS
If 2, A?????? because AFFECTS was 3 and the only difference between AFFECTS and EFFECTS is the whole A-E thing.
If 4, E?????? because AFFECTS was 3 and the only difference between AFFECTS and EFFECTS is the whole A-E thing.
BOYS
If 1, BU?? because BOYS was 1 and the only difference between BOYS and BUYS is the whole O-U thing.
If 3, BO?? because BOYS was 1 and the only difference between BOYS and BUYS is the whole O-U thing.
BUYS
If 0, G??? because BUYS was 1 and the only difference between GUYS and BUYS is the whole G-B thing.
If 2, B??? because BUYS was 1 and the only difference between GUYS and BUYS is the whole G-B thing.