I read this background article the other day: Solar radiation (or sunlight) is the energy Earth receives from the Sun. Earth also emits radiation back into space, but at longer wavelengths that we cannot see. Part of the incoming and emitted radiation is absorbed or reflected by the atmosphere. In May 2017, glints of light, seen as twinkling from an orbiting satellite a million miles away, were found to be reflected light from ice crystals in the atmosphere. I am facing a new situation today: Mark was studying the effect of Sun's radiations on Earth. To that end, he studied Sun's radiations, which he labeled as rad A. Then he studied Earth's radiations, which he labeled as rad B. He also learned that longer wavelength radiations would produce heat. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which radiation would less likely make the atmosphere warm, rad A or rad B?
Ans: rad A

I read this background article the other day: In grassland, much of the organic matter added to the soil is from the deep, fibrous, grass root systems. By contrast, tree leaves falling on the forest floor are the principal source of soil organic matter in the forest. Another difference is the frequent occurrence in the grasslands of fires that destroy large amounts of aboveground material but stimulate even greater contributions from roots. Also, the much greater acidity under any forests inhibits the action of certain soil organisms that otherwise would mix much of the surface litter into the mineral soil. As a result, the soils under grasslands generally develop a thicker A horizon with a deeper distribution of organic matter than in comparable soils under forests, which characteristically store most of their organic matter in the forest floor (O horizon) and thin A horizon. I am facing a new situation today: Kim and Jane inherited some land. Kim inherited some grassland, while Jane inherited a forest. They both took good care of their properties. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which person inherited a parcel with a thicker A horizon?
Ans: Kim

I read this background article the other day: Prokaryotes have a different way to increase genetic variation. It's called genetic transfer or bacterial conjugation . It can occur in two ways. One way is when cells "grab" stray pieces of DNA from their environment. The other way is when cells directly exchange DNA (usually plasmids) with other cells. For example, as shown in Figure below , the donor cell makes a structure called an F pilus , or sex pilus. The F pilus attaches one cell to another cell. The membranes of the two cells merge and genetic material, usually a plasmid , moves into the recipient cell. Genetic transfer makes bacteria very useful in biotechnology. It can be used to create bacterial cells that carry new genes. I am facing a new situation today: Two researches studied living organisms, Joe studied eukaryotes, while Bill studied prokaryotes. They were fascinated by genetic variation. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which researcher observed more genetic transfer taking place?
Ans: Bill

I read this background article the other day: As shown here, pressure decreases to less than 25% of ground-level atmospheric pressure when we get to an altitude of about six miles. Since this is a common cruising altitude for commercial airplanes, pressurized cabins are needed for the comfort and survival of the passengers. This is because the density of the air decreases along with the decreasing air pressure, so there is less oxygen in a breath of air. You've probably noticed this effect in high-mountain areas, as it often feels harder to breath. I am facing a new situation today: John likes to ride on hot air balloon. Last month he rode on a balloon with his friend Keith. First they were at the ground-level. They called it camp A. Then they rose to the height of three miles. They called it camp B. Eventually, they reached six miles above ground. They called it camp C. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Would the air be denser or thinner at camp C than at camp B?
Ans: thinner