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.

Background Paragraph: Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure below ). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. 
Story: Two neighboring counties used different agricultural methods on their farm fields. Cook county used many fertilizers and pesticides, while Dane county used only organic methods and no pesticides. As a result, the waters in Dane county were cleaner. 
Question: Which county contaminated fewer water wells?
Dane.

Background Paragraph: Storing large volumes of data – When storing XML to either file or database, the volume of data a system produces can often exceed reasonable limits, with a number of detriments: the access times go up as more data is read, CPU load goes up as XML data takes more power to process, and storage costs go up. By storing XML data in Fast Infoset format, data volume may be reduced by as much as 80 percent. 
Story: Antwan had a busy day storing XML. In the morning, he filled up a hard drive with XML. In the afternoon, he filled up a few hard drives with XML. At night, he filled up many hard drives with XML. 
Question: What time did the access times go up the most: afternoon or night?
night.

Background Paragraph: Surface temperature differences in turn cause pressure differences. A hot surface warms the air above it causing it to expand and lower the density and the resulting surface air pressure. The resulting horizontal pressure gradient moves the air from higher to lower pressure regions, creating a wind, and the Earth's rotation then causes deflection of this air flow due to the Coriolis effect. The simple systems thus formed can then display emergent behaviour to produce more complex systems and thus other weather phenomena.  Large scale examples include the Hadley cell while a smaller scale example would be coastal breezes. 
Story: Mark was visiting southern Africa as an exchange student. He was amazed by the beauty of Namib Desert, which is located mostly in Namibia. He kind of enjoyed the hot surface of the desert. Next to Namib desert is the grasslands of  Botswana. He noticed that the surface temperature was much lower there. 
Question: Which place would have higher surface air pressure, Namibia or Botswana?

Botswana.