In this task, you are given a question and answer for that. The answer will fill in the blank or will complete the unfinished question. Your task is to provide an explanation based on the given question or fill-in-the-blank statement, and answer.

[Q]: Question: When we lower the temperature of water it becomes 
 Answer: more dense
[A]: 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.


[Q]: Question: Sinking lower in the mesosphere, we encounter _____ temperatures. 
 Answer: higher
[A]: In the mesosphere, temperature decreases as altitude increases.


[Q]: Question: A rocket should be able to fly higher if its mass were 
 Answer: lower
[A]:
By using multiple stages, empty fuel containers could drop away. This reduced the mass of the rocket so that it could fly higher.