A:C,H,O,N
B:C,H,O,N,P
C:C,H,O,S,P
D:C,H,O,Mg,Fe
8×4=____ 12×3=____ 80×4 =____ 120×3=____ 8×40=____
12×30=____ 80×40= ____ 120×30= ____ 800×40=____ 1200×30=____