The milkman in our society started carrying a lactometer. His move was well appreciated by the society members.
$(a)$ What is the use of a lactometer? On what principle does it work?
$(b)$ What values of the milkman are shown by this move?

Name the major nutrient which we get from fish.

Differentiate between compost and vermicompost.

On a voyage in their yacht,John and his father came across an iceberg. John advised his father to keep away from the iceberg. His father said that it is just a small piece of ice jutting out of the sea and there is nothing to bother. John told his father that icebergs are dangerous and narrated the story of the ship $Titanic$,which was sunk by an iceberg. John explained to his father why the iceberg was dangerous. This convinced his father,and they steered clear of the iceberg.
$(a)$ Why are icebergs in the sea dangerous?
$(b)$ What values are possessed by John and his father?

Sameer once went to his granny's home with his family and he saw his granny serving water from an earthen pot and was surprised to see that and asked granny why she has kept that earthen pot for storing water. His granny then answered him that it keeps the water cool during summers,he then smiled and thanked her.
$(a)$ According to you,how does water kept in an earthen pot become cool during summers?
$(b)$ What kind of qualities are shown by Sameer?

In agricultural practices,higher input gives higher yield. Discuss how?