As greenhouse gases increase, changes will be more extreme.  Having read the above passage, choose the right answer to the following question (choices are increases or stays the same ):   When we have a lot of greenhouse gases in the air what happens to the temperature increases or stays the same?
increases

When a volume of water is cooled, the molecules move less vigorously, so same number of molecules takes up less space and the water is denser.  Having read the above passage, choose the right answer to the following question (choices are increases or decreases ):   If Mona fills up a cup with water and places that water into the oven, what happens to the density of the water as it heats up increases or decreases?
decreases

Lighter, more streamlined vehicles need less energy.  Having read the above passage, choose the right answer to the following question (choices are increase or decrease ):   Jim is designing a new car and playing around with different materials. If he were to decrease the weight of the vehicle, what would happen to the fuel efficiency of that vehicle? It would increase or decrease?
increase