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.
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Question: Background Paragraph: Air pollution is harmful to human beings and other living things. About 22 million people die from air pollution each year. Breathing polluted air increases the risk of developing lung diseases such as asthma and lung cancer. Breathing bad air also increases the chances of dying from other diseases. Children are most likely to be affected by air pollution. That’s because their lungs are still developing and growing. Children also take in more air for their size than adults do. Some air pollutants damage the environment as well as the health of living things. The type of damage depends on the pollutant. Air pollution can also harm the environment. 
Story: Two sister cities were part of an air pollution study. While Prague had big air pollution problems, Belfast was eco-friendly and its inhabitants were healthy. 
Question: Which city had fewer people with an increased chance of developing lung disease?

Answer: Belfast.


Question: Background Paragraph: A large log placed in a fire will burn relatively slowly. If the same mass of wood were added to the fire in the form of small twigs, they would burn much more quickly. This is because the twigs provide a greater surface area than the log does. An increase in the surface area of a reactant increases the rate of a reaction. Surface area is larger when a given amount of a solid is present as smaller particles. A powdered reactant has a greater surface area than the same reactant as a solid chunk. In order to increase the surface area of a substance, it may be ground into smaller particles or dissolved into a liquid. In solution, the dissolved particles are separated from each other and will react more quickly with other reactants. 
Story: Two groups of friends went camping , but camped separately a few hundred yards away and started a fire each. Both groups had the same volume of wood. Group P had larger logs, while group Q had small twigs, sawdust and kindlings. 
Question: Which group had wood that provided a smaller surface area for the fire to burn?

Answer: Group P.


Question: Background Paragraph: Using longitudinal data from over 100 countries, Diener and his colleagues showed that rich countries are in general happier than poor countries (Diener, Tay, & Oishi, 2013).[17] Also, life satisfaction for most countries goes up as they become wealthier over time. Diener identified three factors that influence the relationship between income and SWB. Namely, rising income most likely results in higher SWB when it leads to greater optimism, financial satisfaction and household material prosperity among citizens. Furthermore, Diener and his colleagues investigated the relationship between income and different elements of SWB. They illustrated that income has stronger influence on people’s evaluation of their lives than the positive or negative emotions they experience over time (Diener, Kahneman, Tov, & Arora, 2010).[18] The study points to the necessity to evaluate different elements of SWB separately instead of treating happiness as a single entity. 
Story: Two neighboring countries implemented different sets of economic reforms. The reforms took over a decade to implement, but the effects were not similar at all. Redvania was more prosperous and it became much richer, while Blueland stagflated and the inhabitants were not pleased with the outcome. 
Question: Which country had greater optimism after 10 years?

Answer:
Redvania.