10. what creates an area of high pressure air?

Through Fronts which are how air masses differ from each other stating the difference. I think.

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.