I read this background article the other day: The ozone layer is contained within the stratosphere. In this layer ozone concentrations are about 2 to 8 parts per million, which is much higher than in the lower atmosphere but still very small compared to the main components of the atmosphere. It is mainly located in the lower portion of the stratosphere from about 1535 km (9.321.7 mi; 49,000115,000 ft), though the thickness varies seasonally and geographically. About 90% of the ozone in Earth's atmosphere is contained in the stratosphere. I am facing a new situation today: The ozone layer helps organisms by protecting them from Sun's ultraviolet radiation. To find the usefulness of ozone layer Mike wanted to see how much ozone are there in the atmosphere. He then collected three samples of atmosphere, sample A sample B, and sample C. Sample A was collected from the upper portion of the stratosphere. Sample B was collected from the lower portion of the stratosphere. Sample C was collected from the lower atmosphere. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which sample's layer would protect less from ultraviolet radiation, sample A or sample B?
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Answer: sample A

I read this background article the other day: Hemophilia is the name of a group of hereditary diseases that affect the body's ability to control blood clotting. Hemophilia is caused by a lack of clotting factors in the blood. Clotting factors are normally released by platelets. Since people with hemophilia cannot produce clots, any cut can put a person at risk of bleeding to death. The risk of internal bleeding is also increased in hemophilia, especially into muscles and joints. This disease affected the royal families of Europe. I am facing a new situation today: Two cousins went for a blood test. Tim found out he had hemophilia, while John was normal. Tim had to start taking medication. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which cousin has a lack of clotting factors in the blood?
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Answer: Tim

I read this background article the other day: Rain dissolves fertilizer in the soil. Runoff carries it away. The fertilizer ends up in bodies of water, from ponds to oceans. Nitrogen is a fertilizer in the water. Since there is a lot of nitrogen, it causes algae to grow out of control. Pictured below is a pond covered with algae ( Figure below ). Algae use up carbon dioxide in the water. After the algae die, decomposers break down the dead tissue. The decomposers use up all the oxygen in the water. This creates a dead zone. A dead zone is an area in a body of water where nothing grows because there is too little oxygen. There is a large dead zone in the Gulf of Mexico ( Figure below ). The U.S. states outlined on the map have rivers that drain into the Gulf of Mexico. The rivers drain vast agricultural lands. The water carries fertilizer from these areas into the Gulf. I am facing a new situation today: Iceland and Ireland both used agriculture as a the main component of their economies. Ireland used lots of fertilizer and had big environmental problems as a result. Iceland does a lot of greenhouse agriculture using geothermal energy, so it is more protective towards the environment. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which country caused more algae to grow out of control?
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Answer:
Ireland