Questions

I am Prince of a Kingdom. I will be king only if the man who gave me birth i.e, king my father dies.

The moderate temperatures allow Earth to maintain bodies of water into its normal state.

Changes in the bodies of water in terms of volume and structure would change due to the change in temperature. 

It passes through Ambala and Jalandhar

Blueberries are the saddest fruits.

Reason ::

In English some colors are associated with feelings. Blue is associated with sadness. When you "feel blue" it means that you are feeling sad.

Hence, as blueberries has blue in its name it indicates that that is the saddest fruit in logic.

Double fault is associated with which game Tennis. Double fault refers to two consecutive faults during service.