Questions

450 mm Hg denotes the air pressure.

HIV is a virus that damages the immune system. HIV is a lifelong condition, and without treatment, a person with HIV can develop AIDS.

Core of earth is also known as Barysphere.

Someone who receives money in exchange for a promise to pay it back later is called a borrower1, and the person making the loan is the lender.

Footsteps. 

Yes, as you walk forward, you will leave the footstep behind you.

The 180th meridian or antimeridian is the meridian 180° east or west of the Prime Meridian, with which it forms a great circle dividing the earth into the Western and Eastern Hemispheres.

It is common to both east longitude and west longitude.

It is used as the basis for the International Date Line because it mostly passes through the open waters of the Pacific Ocean. However, the meridian passes through Russia and Fiji as well as Antarctica.

New York City Subway has 468 stations (277 of which are under ground) in a network covering 370 km (230 miles)

Pharaoh is the common title of the monarchs of ancient Egypt.

The Pharaoh in ancient Egypt was the political and religious leader of the people and held the titles 'Lord of the Two Lands' and 'High Priest of Every Temple'.