instruction:
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.
question:
Background Paragraph: Unfortunately, the layer of good ozone is being destroyed by air pollution. The chief culprits are chlorine and bromine gases. They are released in aerosol sprays, coolants, and other products. Loss of ozone has created an ozone hole over Antarctica. Ozone depletion results in higher levels of UV radiation reaching Earth. In humans, this increases skin cancers and eye cataracts. It also disturbs the nitrogen cycle, kills plankton, and disrupts ocean food webs. The total loss of the ozone layer would be devastating to most life. It’s rate of loss has slowed with restrictions on pollutants, but it is still at risk. 
Story: Planet Earth and planet Mars both had breathable atmospheres and were inhabited by humans. People of Earth destroyed the ozone layer, people of mars were more careful and protected it. 
Question: Which planet had more people using coolants?
answer:
Earth.


question:
Background Paragraph: During late adulthood, the risk of developing diseases such as cardiovascular diseases and cancer continues to rise. Most people also have a decline in strength and stamina. Their senses may start failing, and their reflex time typically increases. Their immune system also doesn’t work as well as it used to. As a result, common diseases like the flu may become more serious and even lead to death. The majority of late adults develop arthritis, and as many as one in four develop Alzheimer’s disease. 
Story: Mike is a doctor with a local hospital. Today, he is seeing two patients, patient A and patient B. Patient A is in early adulthood, but patient B is in late adulthood. Mike needs to find the differences between the patients to come up with recommendations for them. 
Question: Which patient would see their stamina diminishing, patient A or patient B?
answer:
patient B.


question:
Background Paragraph: Water stratification is when water masses with different properties - salinity (halocline), oxygenation (chemocline), density (pycnocline), temperature (thermocline) - form layers that act as barriers to water mixing which could lead to anoxia or euxinia.[1] These layers are normally arranged according to density, with the least dense water masses sitting above the more dense layers.

Water stratification also creates barriers to nutrient mixing between layers. This can affect the primary production in an area by limiting photosynthetic processes. When nutrients from the benthos cannot travel up into the photic zone, phytoplankton may be limited by nutrient availability. Lower primary production also leads to lower net productivity in waters.[2]. 
Story: Scientists studied water stratification in two saltwater lakes. they were trying to find out why the fish population decreased in Long lake, and was very healthy and abundant in Shoal lake. They found out the phenomenon occurred more often in Long lake, leading to very many unpleasant chain effects. 
Question: Which lake had more phytoplankton?
answer:

Shoal lake.