FastMart, a convenience store chain, is planning to add pancake syrup to the items it sells. FastMart stores do not have shelf space to stock more than one variety of syrup. Surveys of FastMart customers indicate that one-fourth of them prefer low-calorie syrup, while three-fourths prefer regular syrup. Since FastMart's highest priority is to maximize sales, the obvious strategy for it is to stock regular syrup.

Which of the following, if true, most seriously weakens the argument?

Mayor: Migrating shorebirds stop at our beach just to feed on horseshoe-crab eggs, a phenomenon that attracts tourists. To bring more tourists, the town plans to undertake a beach reclamation project to double the area available to crabs for nesting.

Birdwatcher: Without a high density of crabs on a beach, migrating shorebirds will go hungry because shorebirds only eat eggs that a crab happens to uncover when it is digging its own nest.

Which of the following, if true, would provide the mayor with the strongest counter to the birdwatcher's objection?

A study of high blood pressure treatments found that certain meditation techniques and the most commonly prescribed drugs are equally effective if the selected treatment is followed as directed over the long term. Half the patients given drugs soon stop taking them regularly, whereas eighty percent of the study's participants who were taught meditation techniques were still regularly using them five years later. Therefore, the meditation treatment is the one likely to produce the best results.

Which of the following, if true, most seriously weakens the argument?

Three large companies and seven small companies currently manufacture a product with potential military applications. If the government regulates the industry, it will institute a single set of manufacturing specifications to which all ten companies will have to adhere. In this case, therefore, since none of the seven small companies can afford to convert their production lines to a new set of manufacturing specifications, only the three large companies will be able to remain in business.

Which of the following is an assumption on which the author's argument relies?

The Nile Delta of Egypt was invaded and ruled from 1650 to 1550 B.C. by a people called the Hyksos. Their origin is uncertain, but archaeologists hypothesize that they were Canaanites. In support of this hypothesis, the archaeologists point out that excavations of Avaris, the Hyksos capital in Egypt, have uncovered large numbers of artifacts virtually identical to artifacts produced in Ashkelon, a major city of Canaan at the time of the Hyksos invasion.

In order to evaluate the force of the archaeologists' evidence,it would be most useful to determine which of the following?

Two centuries ago, Tufe Peninsula became separated from the mainland, isolating on the newly formed Tufe Island a population of sunflowers.

This population's descendants grow to be, on average, 40 centimeters shorter than sunflowers found on the mainland. Tufe Island is significantly drier than Tufe Peninsula was. So the current average height of sunflowers is undoubtedly at least partially attributable to changes in Tufe's environmental conditions.

Which of the following is an assumption on which the argument depends?

In Berinia, the age at which people could begin to drink alcohol legally used to be 18. In 1990, in an attempt to reduce alcohol consumption and thereby to reduce alcohol-related traffic deaths among Berinians under 21, the legal drinking age was raised to 21. Alcohol-related traffic deaths among people under 21 have decreased significantly since 1990. Nevertheless, surveys show that people in that age-group drink just as much alcohol as they did before 1990.

Which of the following, if true of Berinia, most helps to resolve the apparent discrepancy?

Sonya: The government of Copeland is raising the cigarette tax. Copeland's cigarette prices will still be reasonably low, so cigarette consumption will probably not be affected much. Consequently, government revenue from the tax will increase.

Raoul: True, smoking is unlikely to decrease, because Copeland's cigarette prices will still not be high. They will, however, no longer be the lowest in the region, so we might begin to see substantial illegal sales of smuggled cigarettes in Copeland.

Raoul responds to Sonya's argument by doing which of the following?

In the late 1980s, the population of sea otters in the North Pacific Ocean began to decline. Of the two plausible explanations for the decline— increased predation by killer whales or disease—disease is the more likely. After all, a concurrent sharp decline in the populations of seals and sea lions was almost certainly caused by a pollution-related disease, which could have spread to sea otters, whereas the population of killer whales did not change noticeably.

Which of the following, if true, most seriously weakens the reasoning?

Which of the following most logically completes the passage?

Each species of moth has an optimal body temperature for effective flight, and when air temperatures fall much below that temperature, the moths typically have to remain inactive on vegetation for extended periods, leaving them highly vulnerable to predators. In general, larger moths can fly faster than smaller ones and hence have a better chance of evading flying predators, but they also have higher optimal body temperatures, which explains why ______.