It can be inferred from the passage that in classifying pheromones as a type of odorant, the researchers referred to in highlight text posit that

According to the passage, the fact that pheromones are processed by the VNO in many animal species has been taken as evidence of which of the following?

The primary purpose of the passage is to

The primary purpose of the passage is to discuss the

According to the passage, which of the following is true of the experiments on domestic hens conducted by Sherwin's research team?

It can be inferred that the author of the passage would be most likely to agree with which of the following statements regarding the results of the recent experiments conducted by Sherwin's research team?

Which of the following most logically completes the argument?

Although the pesticide TDX has been widely used by fruit growers since the early 1960's, a regulation in force since 1960 has prohibited sale of fruit on which any TDX residue can be detected. That regulation is about to be replaced by one that allows sale of fruit on which trace amounts of TDX residue are detected. In fact, however, the change will not allow more TDX on fruit than was allowed in the 1960's, because ______.

The population of desert tortoises in Targland's Red Desert has declined, partly because they are captured for sale as pets and partly because people riding all-terrain vehicles have damaged their habitat. Targland plans to halt this population decline by blocking the current access routes into the desert and announcing new regulations to allow access only on foot. Targland's officials predict that these measures will be adequate, since it is difficult to collect the tortoises without a vehicle.

Which of the following would it be most important to establish in order to evaluate the officials' prediction?

Macrophages are cells that play a role in the response of the immune system of mice and other mammals to invasive organisms such as bacteria. Unlike other mice, mice that are genetically incapable of making these particular cells do not show elevated levels of nitrates when infected with bacteria.

The statements above, if true, provide the most support for which of the following conclusions?

Which of the following most logically completes the argument?

A new drug, taken twice daily for one month, is an effective treatment for a certain disease. The drug now most commonly prescribed for the disease occasionally has serious side effects such as seizures; in field tests, the new drug's side effects, though no worse than mild nausea, turned out to be much more frequent. Nevertheless, the new drug is clearly preferable as a treatment, since _____.

Vitacorp, a manufacturer, wishes to make its information booth at an industry convention more productive in terms of boosting sales.The booth offers information introducing the company's new products and services.To achieve the desired result, Vitacorp's marketing department will attempt to attract more people to the booth.The marketing director's first measure was to instruct each salesperson to call his or her five best customers and personally invite them to visit the booth.

Which of the following, if true, most strongly supports the prediction that the marketing director's first measure will contribute to meeting the goal of boosting sales?

In Brindon County, virtually all of the fasteners-such as nuts, bolts, and screws-used by workshops and manufacturing firms have for several years been supplied by the Brindon Bolt Barn, a specialist wholesaler. In recent months many of Brindon County's workshops and manufacturing firms have closed down, and no new ones have opened. Therefore, the Brindon Bolt Barn will undoubtedly show a sharp decline in sales volume and revenue for this year as compared to last year.

The argument depends on assuming which of the following?

In Rubaria, excellent health care is available to virtually the entire population, whereas very few people in Terland receive adequate medical care. Yet, although the death rate for most diseases is higher in Terland than in Rubaria, the percentage of the male population that dies from prostate cancer is significantly higher in Rubaria than in Terland.

Which of the following, if true, most helps to explain the disparity between the prostate cancer death rate in Rubaria and Terland?

Editorial:In Ledland, unemployed adults receive government assistance. To reduce unemployment, the government proposes to supplement the income of those who accept jobs that pay less than government assistance, thus enabling employers to hire workers cheaply. However, the supplement will not raise any worker's income above what government assistance would provide if he or she were not gainfully employed. Therefore, unemployed people will have no financial incentive to accept jobs that would entitle them to the supplement.

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

Editorial:An arrest made by a Midville police officer is provisional until the officer has taken the suspect to the police station and the watch commander has officially approved the arrest. Such approval is denied if the commander judges that the evidence on which the provisional arrest is based is insufficient. A government efficiency expert has observed that almost all provisional arrests meet the standards for adequacy of evidence that the watch commanders enforce. The expert has therefore recommended that because the officers' time spent obtaining approval is largely wasted, the watch commander's approval no longer be required. This recommendation should be rejected as dangerous, however, since there is no assurance that the watch commanders' standards will continue to be observed once approval is no longer required.

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