Questions

 Main Boot Record is located in sector 0, track 0, head 0, cylinder 0 of the primary active partition.

Ideal Gas Law ::

The Combined gas law or General Gas Equation is obtained by combining Boyle's Law, Charles' Law, and Gay-Lussac's Law. It shows the relationship between the pressure, volume, and temperature for a fixed mass (quantity) of gas:

P1V1T1 = P2V2T2

Hence, the Boyle's law P1V1 = P2T2, relates to ideal gas equation.

A greenhouse gas is a gas in an atmosphere that absorbs and emits radiant energy within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. 

Carbon dioxide is a main greenhouse gas, found in car exhaust pipes.
Methane and nitrous oxide is another type of greenhouse gas.

Oxygen is the only clean gas out there because we need it to survive. Therefore, the only gas that is not a greenhouse gas is Oxygen.

Steel is not a compound or element. Steel is an alloy of iron and carbon and other elements and hence it is a mixture. Because of its high tensile strength and low cost, it is a major component used in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons.