I read this background article the other day: Human beings invented agriculture about 10,000 years ago. This provided a bigger, more dependable food supply. It also allowed people to settle down in villages and cities for the first time. Birth rates went up because there was more food and settled life had other advantages. Death rates also rose because of crowded living conditions and diseases that spread from domestic animals. Because the higher birth rates were matched by higher death rates, the human population continued to grow very slowly. I am facing a new situation today: Brad studied ancient human settlements from 100,000 years ago. His colleague Phil studied human settlement from 8-10,000 years ago. They were both fascinated by their findings. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which colleague studied that more people settled down in villages?
Ans: Phil

I read this background article the other day: Inhaling is an active movement that results from the contraction of a muscle called the diaphragm. The diaphragm is large, sheet-like muscle below the lungs (see Figure below ). When the diaphragm contracts, the ribcage expands and the contents of the abdomen move downward. This results in a larger chest volume, which decreases air pressure inside the lungs. With lower air pressure inside than outside the lungs, air rushes into the lungs. When the diaphragm relaxes, the opposite events occur. The volume of the chest cavity decreases, air pressure inside the lungs increases, and air flows out of the lungs, like air rushing out of a balloon. I am facing a new situation today: Keith is a physician in a local hospital. He is treating a patient with respiratory problem. He looked at two different states of the patient's diaphragm, state A and state B. In state A the the diaphragm contracted, but in state B the diaphragm relaxed. He now needs to figure out other phenomena related to this. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: When would the ribcage expand, state A or state B?
Ans: state A

I read this background article the other day: The ionization energies of the representative elements generally decrease from top to bottom within a group. This trend is explained by the increase in size of the atoms within a group. The valence electron that is being removed is further from the nucleus in the case of a larger atom. The attractive force between the valence electron and the nucleus weakens as the distance between them increases and as the shielding effect increases, resulting in a lower ionization energy for the larger atoms within a group. Although the nucl I am facing a new situation today: Jeremy is studying the periodic table in preparation for a chemistry test next week. Today he is focusing on the elements that all belong to the alkali metals group. He is especially focused on learning about lithium, which is at the top of the group, and cesium, which is at the bottom of the alkali metals group. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: In which element is the shielding effect larger?
Ans: cesium

I read this background article the other day: Water stratification is when water masses with different properties - salinity (halocline), oxygenation (chemocline), density (pycnocline), temperature (thermocline) - form layers that act as barriers to water mixing which could lead to anoxia or euxinia.[1] These layers are normally arranged according to density, with the least dense water masses sitting above the more dense layers. Water stratification also creates barriers to nutrient mixing between layers. This can affect the primary production in an area by limiting photosynthetic processes. When nutrients from the benthos cannot travel up into the photic zone, phytoplankton may be limited by nutrient availability. Lower primary production also leads to lower net productivity in waters.[2] I am facing a new situation today: The marine biologists studied two areas of the Black Sea. Area A, situated at the mouth of the Danube River, which presented high levels of water stratification, because of the fresh water discharged by the river; and area B, situated 35 miles south, where the water was less stratified and more oxygenated. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which of the two areas has lower net productivity?
Ans: Area A