[Q]: I read this background article the other day: The Figure below shows decibel levels of several different sounds. As decibel levels get higher, sound waves have greater intensity and sounds are louder. For every 10-decibel increase in the intensity of sound, loudness is 10 times greater. Therefore, a 30-decibel "quiet" room is 10 times louder than a 20-decibel whisper, and a 40-decibel light rainfall is 100 times louder than the whisper. High-decibel sounds are dangerous. They can damage the ears and cause loss of hearing. I am facing a new situation today: Jeremy works on a construction site operating a jackhammer and a large welding machine. Jeremy is frequently exposed to sounds with high decibel levels due to being around these machines so often. Jeremy's brother, Alexander, on the other hand works in a library. Unlike Jeremy, Alexander is frequently exposed to sounds with very low decibel levels during his work. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Whose ears, Jeremy's or Alexander's, are more at risk of being damaged due to the sounds they encounter frequently?
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[A]: Jeremy's

[Q]: I read this background article the other day: The Hawaiian Islands ( Figure above ) are in the central Pacific Ocean. The islands are volcanoes that increase in age from southeast to northwest. The youngest island is the Big Island of Hawaii at the southeast end of the chain. The volcanoes get older through Maui, Kahoolawe, Lanai, Molokai, Oahu, Kauai, and Niihau Islands through the northwest. The Kilauea volcano on Hawaii has been erupting almost continuously since 1983. There are also eruptions at an underwater volcano called Loih I am facing a new situation today: Pete lived in Alaska, but visited his friend Julia from Hawaii very often. They had many mutual interests, including geology and earthquakes. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which person lived closer to Kauai island?
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[A]: Julia

[Q]: I read this background article the other day: Excess intake of calcium may cause hypercalcaemia. However, because calcium is absorbed rather inefficiently by the intestines, high serum calcium is more likely caused by excessive secretion of parathyroid hormone (PTH) or possibly by excessive intake of vitamin D, both which facilitate calcium absorption. It may also be due to bone destruction that occurs when tumours metastasize within bone. All these conditions result in excess calcium salts being deposited in the heart, blood vessels, or kidneys. Symptoms include anorexia, nausea, vomiting, memory loss, confusion, muscle weakness, increased urination, dehydration, and metabolic bone disease. Chronic hypercalcaemia typically leads to calcification of soft tissue and its serious consequences: for example, calcification can cause loss of elasticity of vascular walls and disruption of laminar blood flowand thence to plaque rupture and thrombosis. Conversely, inadequate calcium or vitamin D intakes may result in hypocalcaemia, often caused also by inadequate secretion of parathyroid hormone or defective PTH receptors in cells. Symptoms include neuromuscular excitability, which potentially causes tetany and disruption of conductivity in cardiac tissue. I am facing a new situation today: Two brothers went to the doctor's office for a medical exam and blood tests. Dan found out he is healthy and had normal blood cholesterol and calcium levels. Ben however, was told that he had a disease called hypercalcaemia and had to start a treatment for that. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which brother didn't have excess calcium salts deposited in the kidneys?
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[A]: Dan

[Q]: I read this background article the other day: About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. I am facing a new situation today: White mountains are often visited by tourists because of the many beautiful caves, stalactites, stalagmites and karst phenomena. Dome mountains are interesting to tourists because they are very massive, of volcanic origin and excellent for climbing. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which mountain has a higher percentage of limestone in its composition?
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[A]:
White