Fill in the blanks:
$(a)$ Photoperiod affects the . . . . . . .
$(b)$ Kharif crops are cultivated from . . . . . . to . . . . . . .
$(c)$ Rabi crops are cultivated from . . . . . . to . . . . . . .
$(d)$ Paddy,maize,green gram,and black gram are . . . . . . crops.
$(e)$ Wheat,gram,pea,and mustard are . . . . . . crops.

What are Rabi and Kharif crops? Give two examples each.

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?

Fertilizers have short-term benefits whereas manures have long-term benefits. Do you agree with this statement? Give three reasons in support of your answer.

$(i)$ State three ways by which pests attack plants.
$(ii)$ Name the chemicals used to control pests.
$(iii)$ Explain why excessive use of such chemicals should be avoided.

Mention the basis of crop selection in intercropping and crop-rotation.