construct an electron transport chain using 3 carriers listed, so that electrons transfer spontaneously?

CoQ/CoQH2 = +0.10V; Fe3+/Fe2+ = +0.771 V; FAD/FADH2 = -0.18; NO2-/NH4+ = +0.44 V;

CO2/glucose = -0.43 V; CO2/CH4 = -0.24V; NAD+/NADH = -0.32 V; H+/H2 = -0.42 V;

O2/H2O = +0.815 V; pyruvate/lactate = -0.19 V; S0/H2S = -0.27 V.

Construct an electron transport chain using 3 carriers listed above, so that electrons are transferred spontaneously from one carrier to the next:

Carrier #1 _____________________________, Carrier #2 ___________________________, Carrier #3 ________________________________

I am not exactly understanding what the question asks. This is what I came up with.

Fe3+ +e- -------> Fe2+ +.771V

FADH2 ---------> FAD+ +2e- +.18V

NAD+ + e- -----> NADH -.32V

Total: all electrons cancel, total V = +.631

Is this correct? so my carriers are Fe3+/Fe2+, FAD+/FADH2, NAD+/NADH?