Suggest two ways to check the rancidity of food articles.

(a) List two observations that are noticed when an iron nail is put inside copper sulphate solution. Write chemical equation for the reaction that occurs. (b) Explain two ways by which rancidity of food materials can be checked.

Suggest two ways of reducing this effect?

Suggest two ways to prevent soil erosion .

Suggest measures to check floods.

The best way to check the soil erosion is

The best way to check the soil erosion is

The best way to check the soil erosion is

The best way to check the soil erosion is