Problem: I read this background article the other day: Soil is well developed in the forest as suggested by the thick humus layers, rich diversity of large trees and animals that live there. In forests, precipitation exceeds evapotranspiration which results in an excess of water that percolates downward through the soil layers. Slow rates of decomposition leads to large amounts of fulvic acid, greatly enhancing chemical weathering. The downward percolation, in conjunction with chemical weathering leaches magnesium (Mg), iron (Fe), and aluminum (Al) from the soil and transports them downward, a process known as podzolization. This process leads to marked contrasts in the appearance and chemistry of the soil layers.  I am facing a new situation today: Two  brothers were land owners. Bill owned 40 acres of forest, , with very well developed soil. His brother Rick owned 40 acres of grasslands, with a poor soil. Rick decided to sell his land.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which brother owned a land which had large amounts of fulvic acid?

A: Bill


Problem: I read this background article the other day: Like water in the ocean, air in the atmosphere exerts pressure that increases with depth. Most gas molecules in the atmosphere are pulled close to Earth’s surface by gravity. As a result, air pressure decreases quickly at lower altitudes and then more slowly at higher altitudes. This is illustrated in Figure below . Air pressure is greatest at sea level, where the depth of the atmosphere is greatest. At higher altitudes, the pressure is less because the depth of the atmosphere is less. For example, on top of Mount Everest, the tallest mountain on Earth, air pressure is only about one-third of the pressure at sea level. At such high altitudes, low air pressure makes it hard to breathe and is dangerous to human health.  I am facing a new situation today: Molly has just moved to a new city for a job she was just hired for. She used to live in a city up in the mountains named Midgar. She liked living there due to the hikes she could go on and seeing the beautiful nature of the hills and mountains. The town she lives in now, Treno, is closer to sea level and is mostly flat plains and farm land. It's a change of scenery, and she hopes she starts to enjoy it more.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Is air pressure in Midgar higher or lower than in Treno?

A: lower


Problem: I read this background article the other day: Cancer is a disease that causes cells to divide out of control. Normally, the body has systems that prevent cells from dividing out of control. But in the case of cancer, these systems fail. Cancer is usually caused by mutations. Mutations are random errors in genes. Mutations that lead to cancer usually happen to genes that control the cell cycle. Because of the mutations, abnormal cells divide uncontrollably. This often leads to the development of a tumor. A tumor is a mass of abnormal tissue. As a tumor grows, it may harm normal tissues around it. Anything that can cause cancer is called a carcinogen . Carcinogens may be pathogens, chemicals, or radiation.  I am facing a new situation today: A team of scientists studied two groups of mice. Group C was exposed to carcinogens, while group N was not.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which group of mice had more cells to divide out of control?

A: Group C


Problem: I read this background article the other day: When humans dig up and use fossil fuels, we have an impact on the carbon cycle ( Figure below ). This carbon is not recycled until it is used by humans. The burning of fossil fuels releases more carbon dioxide into the atmosphere than is used by photosynthesis. So, there is more carbon dioxide entering the atmosphere than is coming out of it. Carbon dioxide is known as a greenhouse gas , since it lets in light energy but does not let heat escape, much like the panes of a greenhouse. The increase of greenhouse gasses in the atmosphere is contributing to a global rise in Earth’s temperature, known as global warming or global climate change.  I am facing a new situation today: Greg is an environmental scientist. He wants to know how earth's atmosphere differed in two different time. To that end, he selected two time periods, time A and time B. Time A is set in the year one thousand when using fossil fuels was not very common. Time B is set in the year two thousand when fossil fuels are used in large quantities.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: In which time more carbon dioxide would be realeased into the atmosphere, time A or time B?

A:
time B