Ecologists:the Scottish Highlands were once the site of extensive forests, but these forests have mostly disappeared and been replaced by peat bogs. The common view is that the Highland's deforestation was caused by human activity, especially agriculture. However, agriculture began in the Highlands less than 2,000 years ago. Peat bogs, which consist of compressed decayed vegetable matter, build up by only about one foot per 1000 years, and, throughout the Highlands, remains of trees in peat bogs are almost all at depth great than four feet. Since climate changes that occurred between 7,000 years and 4,000 years ago favored the development of peat bogs rather than the survival of forests, the deforestation was more likely the result of natural processes than of human activity.

In the ecologist's argument, the two portions in boldfaces play which of the following roles?

The percentage of households with an annual income of more than $40,000 is higher in Merton county than in any other county. However, the percentage of households with an annual income of $60,000 or more is highest in Sommer county.

If the statements above are true, which of the following can properly be concluded on the basis of them?

Making things even more difficult has been general market inactivity lately, if not paralysis, which has provided little in the way of pricing guidance.

Scientists typically do their most creative work before the age of forty. It is commonly thought that this happens because aging by itself brings about a loss of creative capacity. However, a study has found that almost all scientists who produce highly creative work beyond the age of forty entered their fields late and less than a dozen years before their creative breakthroughs. Since creative breakthroughs by scientists under forty also generally occur within a dozen years of the scientists' entry into the field, the study's finding strongly suggests that the real reason why scientists over forty rarely produce highly creative work is not due to age but rather because most have spent too long in their fields.

In the argument given, the two portions in boldface play which of the following roles?

In January of last year the Moviemania chain of movie theaters started propping its popcorn in canola oil, instead of the less healthful coconut oil that it had been using until then. Now Moviemania is planning to switch back, saying that the change has hurt popcorn sales. That claim is false, however, since according to Moviemania's own sales figures, Moviemania sold 5 percent more popcorn last year than in the previous year.

Which of the following, if true, most strongly supports the argument against Moviemania's claim?

Fact: Asthma, a bronchial condition, is much less common ailment than hay fever, an allergic inflammation of the nasal passages.

Fact: Over 95 percent of people who have asthma also suffer from hay fever.

If the information given as facts above is true, which of the following must also be true?

Fearing competition from stores that rent video games for home use, owners of stores that sell video games lobbied for protective legislation. Citing as a precedent legislation that postpones home film rentals until one year after general release to theaters, the video sellers proposed as an equitable solution a plan that would postpone rental of any video game until it had been available for sale for one year.

Which of the following, if true, would support an objection by owners of video rental stores that the fairness of the proposed legislation is not supported by the precedent cited?

Telomerase is an enzyme that is produced only in cells that are actively dividing. For this reason it is generally absent from body tissues in adults. Bone marrow is an exception to this rule, however, since even in adults, bone marrow cells continually divide to replace old blood cells. Cancers are another exception, because their cells are rapidly dividing.

The information provided most strongly supports which of the following?

Environmental organizations want to preserve the land surrounding the Wilgrinn Wilderness Area from residential development. They plan to do this by purchasing that land from the farmers who own it. That plan is ill-conceived: if the farmers did sell their land, they would sell it to the highest bidder, and developers would outbid any other bidders. On the other hand, these farmers will never actually sell any of the land, provided that farming it remains viable. But farming will not remain viable if the farms are left unmodernized, and most of the farmers lack the financial resources modernization requires. And that is exactly why a more sensible preservation strategy would be to assist the farmers to modernize their farms to the extent needed to maintain viability.

In the argument as a whole, the two boldface proportions play which of the following roles?

The city of Workney, in raising bus fares from $1.00 to $1.25, proposed that 18 fare tokens be sold for $20.00 to alleviate the extra burden of the fare increase on the city's low-income residents. Critics suggested alternatively that 9 fare tokens be sold for $10.00, because a $20.00 outlay would be prohibitive for low-income riders.

The alternative proposal depends on which of the following assumptions?