The process of seeding during the extraction of aluminium involves the addition of pure AI(OH)₃ crystals in order to

A. lower the temperature

B. increase the concentration

C. facilitate the precipitation of solid

D. reduce the viscosity of the solution

Which of the following measures is not suitable for controlling water pollution?

A. treating industrial effluent and domestic sewage before discharge into water

B. Controlling the use of agrochemicals

C. recycling industrial and agricultural wastes

D. burning industrial and agricultural wastes before discharge into water ways