You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You need to come up with a question about the story that requires an understanding of the relationship described in the background paragraph. The generated question should not be answerable without both the background and story. Write a question about the story that requires a relationship in the background paragraph to answer. Check whether your question requires both the background paragraph and the story to answer. If your question can be answered by only one of these, try to rewrite your question so that it requires both. Note that "flipping" a word in the question can give rise to a new question where the answer will be different from the original question. Often, "flipping" a word gives rise to flipping the direction of the relationship, for example, from "increase" to "decrease."

Background Paragraph: The primary role of red blood cells in the circulatory system is to transport oxygen to the tissues. The actual carrier of oxygen molecules is the protein hemoglobin, which binds to the oxygen and moves it throughout the body, releasing it in areas where the concentration of dissolved oxygen is low. A certain mutation in the gene for hemoglobin causes a slight change in the structure of this crucial protein, resulting in a disease called sickle-cell anemia. For people with this mutation, the hemoglobin produced by their red blood cells has a tendency to clump together, distorting the shape of the red blood cells and giving rise to the crescent-shaped cells seen above. By understanding the changes in structure that are the underlying cause of this disease, we have developed various ways to treat and manage this illness. 
Story: Doctors studied Dan, a normal patient, whit a normal number of red blood cells, and Jim, a patient that had sickle-cell anemia. The differences were remarkable in terms of overall well-being and health.
Which patient had fewer crescent shaped red blood cells, Dan or Jim?

Background Paragraph: In the study of thermochemical processes, things are viewed from the point of view of the system. A chemical reaction or physical change is endothermic if heat is absorbed by the system from the surroundings. In the course of an endothermic process, the system gains heat from the surroundings and so the temperature of the surroundings decreases. The quantity of heat for a process is represented by the letter . The sign of for an endothermic process is positive because the system is gaining heat. A chemical reaction or physical change is exothermic if heat is released by the system into the surroundings. Because the surroundings is gaining heat from the system, the temperature of the surroundings increases. The sign of for an exothermic process is negative because the system is losing heat. 
Story: Calving is sitting in his kitchen when he decides to play around with some ice and water. He takes an ice cube out of the freezer and puts it on a plate on his kitchen table. He then takes a glass of water and puts it into the freezer. He is curious to see if the ice cube will melt before the water freezes.
Is the ice cube melting an exothermic or endothermic reaction?

Background Paragraph: About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. 
Story: Peter visited two mountain ranges last summer. The Ozarks in Missouri, and the  more massive and younger Colorado Rockies. He loved both ranges, but liked the caves systems and blue holes in the Ozarks a bit more.

Which mountains have a larger percent of limestone?