Questions

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.

In order to protect the operating systems and the system programs from the malfunctioning programs the two mode operations were evolved

System mode

User mode