Q. Continuous passing of Co2 through the mould can decrease the strength of mould and results in a weak mould.
✅ Correct Answer: (B)
false
Explanation: continuous passing of co2 always results in a strong and hard mould. more the passing of co2 more will be the strength of the mould. only the drawback is the decrease in permeability and collapsibility of the mould. much passing of co2 gas results into difficult breathing of the mould.