A student is studying insulation used to keep houses warm. The student builds 10 model houses and uses a different thickness of insulation on each
house. She then measures the temperature inside each model house. What is
the manipulated variable in this experiment?

Why is rain likely when warm, moisture-laden air meets cold air? a) the lighter warm air will rise and cool down, causing condensation and rain. b) the cold air moves faster and pushes the warm air away, causing condensation and rain. c) the moisture in the warm air condenses on contact with the cold air, causing rain to fall. d) the cold air mixes with the warm air, reducing its temperature causing moisture to condense.