Which chemical equation represents a redox reaction?(1 point) 1.) Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(l)
2.) CaO(s) + SiO2(s) → CaSiO3(l)
3.) CaCO3(s) → CaO(s) + CO2(g)
4.) TiCl4(s) + 2H2O(g) → TiO2(s) + 4HCl(g)

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A weight-training program that gradually increases the resistance lifted relies on the progression principle to build strength, where strength is the amount of force a muscle can exert.
The principle of progression states that you should overload gradually and that there is a perfect level of overload in-between a too slow increase and a too rapid increase.