<span>During the stage of internal combustion engine operation in which the piston rises and compresses the fuel in the combustion chamber, the intake and exhaust valves will both be closed. This means that the mixture of fuel and air are compressed, due to the seal around the combustion chamber that has been created by the closure of both of these valves. Hopefully that answered your question for you!</span>
Not 100% sure but I think its the Barail Range. This would affect them by the mountain acting almost like a barrier between them. So they didn't have much interaction.
