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 are also given a question about the story that requires an understanding of the relationship described in the background paragraph and the story. You need to come up with an answer to the given question; the answer will be a span from either the question or the story. In order to correctly answer the given question, you need to understand the relationship mentioned in the background paragraph and should be able to use it to understand that in the story. Your answer can not consist of any word that is not mentioned in any of these: the background paragraph, the story, or the question. You can directly copy and paste a span from the story or the question while answering the given question.

[EX Q]: 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: Bill is going on some trips this week. The first trip on Saturday is to Reginald's Peak. The next trip on Sunday is to Smuggler's Caves. He is very excited to see what both of the sites have to offer!. 
Question: On which day will Bill have a less likely chance to see limestone formations?
[EX A]: Saturday.

[EX Q]: Background Paragraph: Alberta's electrical demand varies throughout the day and across the seasons. When individuals are fixing supper and using home appliances, demand for power goes up, as it does during heat waves and cold snaps. It tapers off during spring and fall. Like other mechanical devices, generators fail from time to time. If they are wind-powered, their output varies with the wind. 
Story: Tony is in charge of a power station in Alberta. He has been tasked with turning on and off generators depending on the demand for power. He has been ordered to try and be efficient as possible, turning off generators in low demand times, and turning them on in high demand times to satisfy needs. On Monday and Tuesday, Alberta saw record high temperatures, and on Thursday and Friday,  things cooled off for a more moderate and comfortable temperature. 
Question: Which days did Tony most likely turn on more generators?
[EX A]: Monday and Tuesday.

[EX Q]: Background Paragraph: Alpine climate is the average weather (climate) for the alpine tundra. The climate becomes colder at high elevations—this characteristic is described by the lapse rate of air: air tends to get colder as it rises, since it expands. The dry adiabatic lapse rate is 10 °C per km (5.5 °F per 1000 ft) of elevation or altitude. Therefore, moving up 100 metres (330 ft) on a mountain is roughly equivalent to moving 80 kilometers (45 miles or 0.75° of latitude) towards the pole. This relationship is only approximate, however, since local factors such as proximity to oceans can drastically modify the climate. 
Story: Two regions of the same country had very different climates because of the different landscapes. East region had an alpine landscape, was situated in the mountains. North region was flat and located at sea level. 
Question: Which region didn't have an alpine tundra?
[EX A]:
North.