Questions

The Rate of doing work or rate of transfer of energy is called Power.

Verification of a login name and password is known as Authentication.

Giraffe has the highest blood pressure among animals. 

This is due to the fact that there is a large pressure drop (~100 mmhg) as the blood is transported from the heart, up the neck, to the brain. This is about twice the normal blood pressure of humans (120/80 mmhg).

Polo is the sport which is played in the largest pitch.

A complete binary tree is a binary tree where all the levels have maximum number of nodes except possibly the last level.

The depth of complete binary tree of n nodes will be Dn=log 2 (n+1) where Dn is the height or depth of the tree and n is the number of nodes.