Shopping in person is an activity that many people loathe. This accounts for the popularity of online shopping, which has few of the hassles of in-person shopping. Online shoppers are able to avoid lines, traffic, and having to hunt around the store for the items they need. With a few keystrokes and a credit card, they can accomplish a task in a few minutes that might have taken hours in "real life."

The claim that shopping in person is an activity that many people loathe plays which of the following roles in the argument?

Though wildfires were once considered a destructive threat to native forests and were thus fought with all available resources when encountered, today it is common for forest management professionals to allow naturally kindled wildfires to burn themselves out so long as they do not directly threaten major population centers.

Which of the following, if true, best helps to explain forest management professionals’ change in response to wildfires?

Though it has held true for more than half a century, the predictive maxim known as Moore’s Law, which famously supposes that the processing power of computer chips will double approximately every two years, will almost certainly fail to hold in the next ten years. Plainly, the only way to ensure that processing power continues to increase at the predicted rate would be either to continue to reduce the size of the transistors that are the source of all chips’ processing power or to fit additional transistors onto each chip. The former is impossible, as the fundamental barrier to further transistor miniaturization, the size of the atoms of silicon of which the transistors are composed, will be reached in but five years’ time, perhaps less. Since reducing the size between chips is similarly constrained by this atomic barrier; thus, the only realistic hope of substantially increasing transistor density that remains is the “sandwiching” of chip components, the further layering of transistor atop transistor. While transistor layering is integral to modern chip design, it, too, is unlikely to develop swiftly enough for the hoped for doubling of processing power to materialize. Sadly, Mr. Moore’s much vaunted prediction will not last the decade.

In the argument given above, the two underlined portions play which of the following roles? 

Though stars are separated from one another by distances nearly unfathomable to our perceptions, the space between is not, as is often thought, entirely devoid of matter. It is, in fact, filled with very low density matter, essentially a “cosmic dust,” minuscule in volume and diffused across almost infinite distances, yet there is still enough present to act as a curtain that obscures the stars that lie behind it. Indeed, if it were not for this “dust” we would see no darkness when we looked to the night sky. It would, instead, be entirely filled by the light of stars.

The two underlined sections play what roles in the passage's argument above?

Mike: We have too many people using each of the fax machines in our office. The high frequency of breakdowns is due to too many people handling the same hardware.

Lisa: We have just as many people working in our office, yet we hardly need any repairs to our machines. Our machines must be more robust than yours.

Lisa's argument would be most strengthened by providing data on the __________.

Research has shown that there is a direct correlation between increased gas prices and use of public transportation in large American cities. A council of American mayors plans to discuss a national campaign to promote the use of public transportation.

The author assumes which of the following about public transportation in American cities?

The current crisis involving student-loan debt has forced many recent college graduates to work multiple jobs, fall behind in paying other debts, or continue living with their parents for many years.  This reality, combined with rising tuition and other costs associated with college, are making higher-education a less attractive option for many high school graduates. America is facing the possibility of having its first generation that is less educated than the previous one.

Of the following, what can be most properly inferred from the passage above?

The music industry, once thought to have completely given itself over to digital recording, has apparently made room for its analog ancestors.  Vinyl records and their accompanying turntables are making a comeback.  Audiophiles have long argued that digital recordings lack both depth and clarity and that music recorded on tape has a much richer sound.  While vinyl may not return to its previous place of prominence in the music world, it seems clear that there is room for both digital and analog recordings in modern music.

Which of the following is an assumption made by the author of the argument above?