Problem: I read this background article the other day: The temperature of a body of water directly affects the amount of dissolved oxygen it can hold. Following Henry's law, as water becomes warmer, oxygen becomes less soluble in it. This property leads to daily anoxic cycles on small geographic scales and seasonal cycles of anoxia on the larger scale. Thus, bodies of water are more vulnerable to anoxic conditions during warmest period of the day and during the summer months. This problem can be further exacerbated in the vicinity of industrial discharge where warm water used to cool machinery is less able to hold oxygen than the basin to which it is released. I am facing a new situation today: Dan visited Twin lakes every year. The interesting fact about them wast that, while Twin I had a very cold water all year, Twin II lake had very warm waters year round. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which body of water had more soluble oxygen?

A: Twin I

Problem: I read this background article the other day: Mantle melting can come about three ways: (1) when the temperature rises, (2) if the pressure lowers (which lowers the melting point), and (3) if water is added, which lowers the melting point. Two of these (1 and 3) might explain why there are volcanoes at convergent plate boundaries: the temperature of the subducting plate increases as it sinks into the hot mantle (1). Sediments lying on top of the subducting plate contain water. As the sediments subduct, the water rises into the overlying mantle material. This lowers the melting temperature of the mantle (3). When the mantle above the subducting plate melts, volcanoes form above it. This leads to volcanoes in an island arc or continental arc. I am facing a new situation today: Ben and Mike both studied earthquakes, while Mike was more interested specifically in mantle melting and related phenomena. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which person studied less about volcanoes at convergent plate boundaries?

A: Ben

Problem: I read this background article the other day: The body's second line of defense against pathogens includes the inflammatory response. If bacteria enter the skin through a scrape, the area may become red, warm, and painful. These are signs of inflammation. Inflammation is one way the body reacts to infections or injuries. Inflammation is caused by chemicals that are released when skin or other tissues are damaged. The chemicals cause nearby blood vessels to dilate, or expand. This increases blood flow to the damaged area, which makes the area red and slightly warm. The chemicals also attract white blood cells called neutrophils to the wound and cause them to leak out of blood vessels into the damaged tissue. I am facing a new situation today: Two medical school students named Dan and Bob learned about the human immune system. Dan studied more about the subject, and became very interested to pursue it more in the future. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which student learned that the infected skin area may become red?

A: Dan

Problem: I read this background article the other day: Recall that air pollution is due to chemical substances and particles released into the air mainly by human actions. When most people think of air pollution, they think of the pollution outdoors. But it is just as easy to have indoor air pollution. Your home or school classroom probably doesn't get much fresh air. Sealing up your home reduces heating and cooling costs. But this also causes air pollution to stay trapped indoors. And people today usually spend a majority of their time indoors. So exposure to indoor air pollution can become a significant health risk. I am facing a new situation today: Patty was a runner and liked hiking so she spent a lot of time outdoors. Her friend Fay sealed up her home and spent most of her time indoors. Both friends lived in an area with moderate to high levels of air pollution and attended a seminar where they learned more about the impact of air pollution on human health. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which friend was exposed to less indoor pollution?

A:
Patty