Once Ram's mother Sunita went to her friend's home along with Ram. On visiting there,Ram saw a wet khus-khus screen hung at the door of the room. He asked his mother why they had hung this screen,and his mother answered that it keeps the room cool. Ram was satisfied and smiled.
$(a)$ According to you,what qualities are possessed by Ram?
$(b)$ How does a wet khus-khus screen hung at the door keep the room cool?

Find out the correct sentence:
$(i)$ Hybridisation means crossing between genetically dissimilar plants.
$(ii)$ Cross between two varieties is called as interspecific hybridisation.
$(iii)$ Introducing genes of desired character into a plant gives genetically modified crop.
$(iv)$ Cross between plants of two species is called as inter-varietal hybridisation.

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

Bhetki,mullets,pearl spots and prawns are some of marine fish of high economic value.

Jessica saw her mother rotating a milk churner in a container of milk. She was surprised and asked her mother why she was doing that. Her mother smiled and explained that she was separating cream from milk,which would be used in various dishes.
$(a)$ What kind of qualities are shown by Jessica's mother?
$(b)$ How is cream easily separated from milk by a milk churner?

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.