Answer:
Generation and consumption should be set to zero.
Explanation:
In the case where the species are non-reactive, the Generation and Consumption should be set to zero.
The Generation term becomes different from zero when there is a reaction that changes the mass balance and this change didn't come from the inflow of mass.
The Consumption term also refers to a reaction where reactants are being consumed in a chemical reaction, differentiating it from the exit flow.
