Coal is used to produce electricity by burning in coal-fire power stations.
Coal-fired power stations are inherently modular.
Coal is used to produce electricity by burning in inherently modular stations.
coal is used to produce electricity by burning in inherently modular what?

(a) heat
(b) stations
(c) trees
(d) heat energy
(e) similar
(f) cells
(g) adding heat
(h) engines