TASK DEFINITION: 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.
PROBLEM: Background Paragraph: Tropical forests (rainforests) receive more insolation and rainfall over longer growing seasons than any other environment on earth. With these elevated temperatures, insolation and rainfall, biomass is extremely productive leading to the production of as much as 800 grams of carbon per square meter per year. Higher temperatures and larger amounts of water contribute to higher rates of chemical weathering. Increased rates of decomposition cause smaller amounts of fulvic acid to percolate and leach metals from the zone of active weathering. Thus, in stark contrast to soil in forests, tropical forests have little to no podzolization and therefore do not have marked visual and chemical contrasts with the soil layers. Instead, the mobile metals Mg, Fe and Al are precipitated as oxide minerals giving the soil a rusty red color. 
Story: John was studying the characteristics of tropical forests. For that, he chose forests in Laos. To compare the forests in Laos with the temperate zone forests he chose forests in Ireland. He could clearly see that how they differed in important ways. 
Question: Would forests in Laos produce less or more biomass than forests in Ireland?

SOLUTION: more.

PROBLEM: Background Paragraph: Almost all earthquakes occur at plate boundaries. All types of plate boundaries have earthquakes. Convection within the Earth causes the plates to move. As the plates move, stresses build. When the stresses build too much, the rocks break. The break releases the energy that was stored in the rocks. The sudden release of energy is an earthquake. During an earthquake the rocks usually move several centimeters. Rarely, they may move as much as a few meters. Elastic rebound theory describes how earthquakes occur ( Figure below ). 
Story: Tim the seismologist studied data from two cities: Tokyo and Kansas City. Tokyo experienced many more earthquakes than Kansas City. 
Question: Which city experiences more energy release because of rocks breaking?

SOLUTION: Tokyo.

PROBLEM: Background Paragraph: Sand mining is a direct cause of erosion, and impacts the local wildlife.[2] Various animals depend on sandy beaches for nesting clutches, and mining has led to the near extinction of gharials (a species of crocodile) in India. Disturbance of underwater and coastal sand causes turbidity in the water, which is harmful for organisms like coral that need sunlight. It can also destroy fisheries, financially harming their operators.

Removal of physical coastal barriers, such as dunes, sometimes leads to flooding of beachside communities, and the destruction of picturesque beaches causes tourism to dissipate. Sand mining is regulated by law in many places, but is often done illegally.[3] Globally, it is a $70 billion industry, with sand selling at up to $90 per cubic yard.[4]. 
Story: Sand mining in the north coastal region was stopped 20 years ago, but it still continues to this day in the south region. Both fishing communities there are still prosperous, but the southern one had a couple of bad years, with fish and other marine wildlife becoming more scarce. The southern beach had erosion problems as well. The northern beach recovered, and is suitable for tourism. 
Question: Which region has a lower water turbidity?

SOLUTION:
northern.