Why should biological control methods be preferred for protecting crops?

Which of the following are exotic breeds of cattle?

How are Indian bees different from Italian bees?

Preventive and control measures adopted for the storage of grains include

List two desirable traits for fodder crops.

While studying about irrigation in her textbook,Bhanika read that proper irrigation is very important for the success of crops. Ensuring that the crops get water at the right stages during their growing season can increase the expected yields of any crop. She then thought about how irrigation is necessary in daily life,and considered sources like wells,rivers,and tanks as irrigation systems. She also shared this knowledge about irrigation systems with her friends.
$(a)$ According to you,what kind of qualities are seen in Bhanika?
$(b)$ Explain how rivers are an effective irrigation system.