Distinguish between intercropping and mixed cropping. List any two advantages of intercropping over mixed cropping.

Why is there a need for varietal improvement?

It is observed that the number of asthmatic patients is increasing day by day. It is due to urbanization,industrialization,and excessive use of vehicles. Sidak's mother took some initiatives to reduce this problem. She,along with her son and his friends,prepared data on the destinations colony people visit,the different routes taken,and the timings of their jobs,and arranged for carpooling.
$(a)$ Explain the reason for the growing number of asthmatic patients.
$(b)$ Explain the values shown by Sidak's mother.
$(c)$ Suggest other methods to reduce this problem.

$(i)$ Mr. Ramdin,an educated farmer,convinces his friends to use fertilizers judiciously. Why?
$(ii)$ Which two values of Ramdin impress you?

$(i)$ List three factors on which cultivation practices and crop yield depend.
$(ii)$ Name three stages involved in farming practices.

$A$ teacher mentioned organisms that enrich the soil with nutrients. Rahila was curious to know more about them. She searched the internet and learned about $Rhizobium$ bacteria and cyanobacteria.
$(i)$ What are bio-fertilizers?
$(ii)$ Explain how any one of the organisms mentioned above enriches the soil with nutrients.
$(iii)$ Why was Rahila curious to get more information?