TASK DEFINITION: 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.
PROBLEM: Question: Milo owns two telescopes, one at the top of a mountain and one at the base. If he looks through the one at the top of the mountain, how much interference can he expect compared to the one at the bottom of the mountain? 
 Answer: less

SOLUTION: Many observatories are built on high mountains. There is less air above the telescope, so there is less interference from the atmosphere.

PROBLEM: Question: Given two equal measures of water by volume, which would be lighter 
 Answer: distilled water?

SOLUTION: Water becomes more dense when it is colder and when it has more salt.

PROBLEM: Question: Between the United States, the richest nation in the world, and the Democratic Republic of Congo, the poorest nation in the world, which uses less gasoline per capita, 
 Answer: the people in the Democratic Republic of Congo?

SOLUTION:
Richer nations use far more energy resources, especially fossil fuels, than poorer nations do.