Problem: I read this background article the other day: Evidence from seismology, heat flow at the surface, and mineral physics is combined with the Earth's mass and moment of inertia to infer models of the Earth's interior its composition, density, temperature, pressure. For example, the Earth's mean specific gravity (5.515) is far higher than the typical specific gravity of rocks at the surface (2.73.3), implying that the deeper material is denser. This is also implied by its low moment of inertia ( 0.33 M R2, compared to 0.4 M R2 for a sphere of constant density). However, some of the density increase is compression under the enormous pressures inside the Earth. The effect of pressure can be calculated using the AdamsWilliamson equation. The conclusion is that pressure alone cannot account for the increase in density. Instead, we know that the Earth's core is composed of an alloy of iron and other minerals.Reconstructions of seismic waves in the deep interior of the Earth show that there are no S-waves in the outer core. This indicates that the outer core is liquid, because liquids cannot support shear. The outer core is liquid, and the motion of this highly conductive fluid generates the Earth's field. Earth's inner core, however, is solid because of the enormous pressure.Reconstruction of seismic reflections in the deep interior indicate some major discontinuities in seismic velocities that demarcate the major zones of the Earth: inner core, outer core, mantle, lithosphere and crust. The mantle itself is divided into the upper mantle, transition zone, lower mantle and D layer. Between the crust and the mantle is the Mohorovicic discontinuity.The seismic model of the Earth does not by itself determine the composition of the layers. For a complete model of the Earth, mineral physics is needed to interpret seismic velocities in terms of composition. The mineral properties are temperature-dependent, so the geotherm must also be determined. This requires physical theory for thermal conduction and convection and the heat contribution of radioactive elements.... I am facing a new situation today: John is a geologist. He was trying to figure out how the Earth's inner core is made. To that end, he compared earth's physical characteristics to available items. First he took a sample of surface rock, which he labeled as item B. Then he took a sphere of constant density, which he labeled as item C. Finally, he labeled the Earth as item A. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which would have higher moment of intertia, item A or item C?

A: item C

Problem: I read this background article the other day: Sometimes muscles and tendons get injured when a person starts doing an activity before they have warmed up properly. A warm up is a slow increase in the intensity of a physical activity that prepares muscles for an activity. Warming up increases the blood flow to the muscles and increases the heart rate. Warmed-up muscles and tendons are less likely to get injured. For example, before running or playing soccer, a person might jog slowly to warm muscles and increase their heart rate. Even elite athletes need to warm up ( Figure below ). I am facing a new situation today: Beth and Sally are both on the high school basketball team and are about to play a match against their rival school. This match is extremely important, and students from both schools always turn out in droves to support their team. Last year, Beth and Sally's team lost so they are extra motivated this year to win. Before the game, Beth spends her time running in place and doing jumping jacks to prepare, and Sally spends her time talking to her friends who are sitting in the bleachers cheering the team on. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Who has more blood flowing to their muscles?

A: Beth

Problem: I read this background article the other day: Ecology is the study of ecosystems. An ecosystem consists of all the living and nonliving components of the habitat. Whereas nutrients and certain elements are recycled through ecosystems, energy moves in just one direction. Many interactions among species within an ecosystem are centered around the flow of energy. The formation of ecosystems, from new land to current habitats, is usually based on the pioneer species, and these species are able to live in an area due to the nonliving factors, such as the climate, the soil and the amount of rainfall, of that area. The populations within an ecosystem also determine the stability of the system. Recent tremendous increases in the human population have raised many important ecological issues. I am facing a new situation today: Two friends were into natural sciences. Tom was more into Geology, while Rick studied Ecology. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which student read more about living components of the habitat?

A: Rick

Problem: I read this background article the other day: Besides anthropogenic productivity of the land, the biodiversity of degraded land also declines, as previously mentioned.[12] With less biodiversity, this ecosystem is less adaptable to when disasters strike it[11][8] It has a smaller available food supply, in terms of plants, for animals, who then may die out or more likely may relocate. Proof of this decline is that presently 15-20% of Tibetan Plateau species are now considered endangered; and now because of this animal and plant absence, the soil quality of these degraded lands is very poor.[1] It does not hold the necessary nutrients, such as water, nitrogen, and carbon, essential to either supporting life or inviting life back to that land.[6] As a result of such carbon and nitrogen loss in the Tibetan Plateau, $8,033/ha and $13,315/ha were respectively lost in economic terms. Soils are further weakened by dust storms whose frequency increases because of degradation.[11][4] Erosion of soil becomes a bigger problem, since no longer are there as many plants to anchor in the soil. In the northern Chinese province alone, 400 million are affected every year with an associated 54 billion yuan of annual economic loss due to grassland degradation. I am facing a new situation today: Xi province started sustainable agriculture and permaculture 40 years ago, while Huan province still uses conventional methods of cultivation. Animals grazing the fields extensively lead to desertification, the loss of carbon and nitrogen in the soil, and other problems. Permaculture was beneficial in Xi province, they re-built 10 inches of top soil in 10 years which is 6 times faster than the natural rate, which lead to a more diverse ecosystem and more biodiversity. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which province had a lesser food production due to agriculture practices?

A:
Huan province