In the years since the city of London imposed strict air-pollution regulations on local industry, the number of bird species seen in and around London has increased dramatically. Similar air-pollution rules should be imposed in other major cities.
Each of the following is an assumption made in the argument above EXCEPT:

A. In most major cities, air-pollution problems are caused almost entirely by local industry.

B. Air-pollution regulations on industry have a significant impact on the quality of the air.

C. The air-pollution problems of other major cities are basically similar to those once suffered by London.

D. An increase in the number of bird species in and around a city is desirable.

E. The increased sightings of bird species in and around London reflect an actual increase in the number of species in the area.

Informed people generally assimilate information from several divergent sources before coming to an opinion. However, most popular news organizations view foreign affairs solely through the eyes of our State Department. In reporting the political crisis in foreign country B, news organizations must endeavor to find alternative sources of information.

 Which of the following inferences can be drawn from the argument above? 

(A) To the degree that a news source gives an account of another country that mirrors that of our State Department, that reporting is suspect.

(B) To protect their integrity, news media should avoid the influence of State Department releases in their coverage of foreign affairs.

(C) Reporting that is not influenced by the State Department is usually more accurate than are other accounts.

(D) The alternative sources of information mentioned in the passage would probably not share the same views as the State Department

(E) A report cannot be seen as influenced by the State Department if it accurately depicts the events in a foreign country.

In the course of her researches, a historian recently found two documents mentioning the same person, Erich Schnitzler. One, dated May 3, 1739, is a record of Schnitzler’s arrest for peddling without a license. The second, undated, is a statement by Schnitzler asserting that he has been peddling off and on for 20 years. 

The facts above best support which of the following conclusions? 

(A) Schnitzler started peddling around 1719. 

(B) Schnitzler was arrested repeatedly for peddling. 

(C) The undated document was written before 1765. 

(D) The arrest record was written after the undated document.

(E) The arrest record provides better evidence that Schnitzler peddled than does the undated document.

Over the last century, paleontologists have used small differences between fossil specimens to classify triceratops into sixteen species. This classification is unjustified, however, since the specimens used to distinguish eleven of the species come from animals that lived in the same area at the same time.

Which of the following, if true, would enable the conclusion of the argument to be properly drawn?

(A) Not every species that lived in a given area is preserved as a fossil.

(B) At least one individual of every true species of triceratops has been discovered as a fossil specimen.

(C) No geographical area ever supports more than three similar species at the same time.

(D) In many species, individuals display quite marked variation.

(E) Differences between fossil specimens of triceratops that came from the same area are no less distinctive than differences between specimens that came from different areas.

Damaged nerves in the spinal cord do not regenerate themselves naturally, nor even under the spur of nerve-growth stimulants. The reason, recently discovered, is the presence of nerve-growth inhibitors in the spinal cord. Antibodies that deactivate those inhibitors have now been developed. Clearly, then, nerve repair will be a standard medical procedure in the foreseeable future. 

Which of the following, if true, casts the most serious doubt on the accuracy of the prediction above? 

(A) Prevention of the regeneration of damaged nerves is merely a by-product of the main function in the human body of the substances inhibiting nerve growth. 

(B) Certain nerve-growth stimulants have similar chemical structures to those of the antibodies against nerve-growth inhibitors. 

(C) Nerves in the brain are similar to nerves in the spinal cord in their inability to regenerate themselves naturally. 

(D) Researchers have been able to stimulate the growth of nerves not located in the spinal cord by using only nerve-growth stimulants.

(E) Deactivating the substances inhibiting nerve growth for an extended period would require a steady supply of antibodies.

Advertisement: For sinus pain, three out of four hospitals give their patients Novex. So when you want the most effective painkiller for sinus pain, Novex is the one to choose.

Which of the following, if true, most seriously undermines the advertisement’s argument?

(A) Some competing brands of painkillers are intended to reduce other kinds of pain in addition to sinus pain.

(B) Many hospitals that do not usually use Novex will do so for those patients who cannot tolerate the drug the hospitals usually use.

(C) Many drug manufacturers increase sales of their products to hospitals by selling these products to the hospitals at the lowest price the manufacturers can afford.

(D) Unlike some competing brands of painkillers, Novex is available from pharmacies without a doctor’s prescription

(E) In clinical trials Novex has been found more effective than competing brands of painkillers that have been on the market longer than Novex.

In 1986, the city of Los Diablos had 20 days on which air pollution reached unhealthful amounts and a smog alert was put into effect. In early 1987, new air pollution control measures were enacted, but the city had smog alerts on 31 days that year and on 39 days the following year. In 1989, however, the number of smog alerts in Los Diablos dropped to sixteen. The main air pollutants in Los Diablos are ozone and carbon monoxide, and since 1986 the levels of both have been monitored by gas spectrography

Which of the following statements, assuming that each is true, would be LEAST helpful in explaining the air pollution levels in Los Diablos between 1986 and 1989?

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
(B) In December of 1988 a new and far more accurate gas spectrometer was invented.
(C) In February of 1989, the Pollution Control Board of Los Diablos revised the scale used to determine the amount of air pollution considered unhealthful.
(D) In 1988 the mayor of Los Diablos was found to have accepted large campaign donations from local industries and to have exempted those same industries from air pollution control measures.
(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.

Dr. A: The new influenza vaccine is useless at best and possibly dangerous. I would never use it on a patient.

Dr. B: But three studies published in the Journal of Medical Associates have rated that vaccine as unusually effective.

Dr. A: The studies must have been faulty because the vaccine is worthless.

In which of the following is the reasoning most similar to that of Dr. A?

(A) Three of my patients have been harmed by that vaccine during the past three weeks, so the vaccine is unsafe.

(B) Jerrold Jersey recommends this milk, and I don’t trust Jerrold Jersey, so I won’t buy this milk.

(C) Wingzz tennis balls perform best because they are far more effective than any other tennis balls.

(D) I’m buying Vim Vitamins. Doctors recommend them more often than they recommend any other vitamins, so Vim Vitamins must be good.

(E) Since University of Muldoon graduates score about 20 percent higher than average on the GMAT, Sheila Lee, a University of Muldoon graduate, will score about 20 percent higher than average when she takes the GMAT.

George Bernard Shaw wrote: “That any sane nation, having observed that you could provide for the supply of bread by giving bakers a pecuniary interest in baking for you, should go on to give a surgeon a pecuniary interest in cutting off your leg is enough to make one despair of political humanity.”

Shaw’s statement would best serve as an illustration in an argument criticizing which of the following?

(A) Dentists who perform unnecessary dental work in order to earn a profit

(B) Doctors who increase their profits by specializing only in diseases that affect a large percentage of the population

(C) Grocers who raise the price of food in order to increase their profit margins

(D) Oil companies that decrease the price of their oil in order to increase their market share

(E) Bakers and surgeons who earn a profit by supplying other peoples’ basic needs

Exports of United States wood pulp will rise considerably during this year. The reason for the rise is that the falling value of the dollar will make it cheaper for paper manufacturers in Japan and Western Europe to buy American wood pulp than to get it from any other source.

Which of the following is an assumption made in drawing the conclusion above?

(A) Factory output of paper products in Japan and Western Europe will increase sharply during this year.

(B) The quality of the wood pulp produced in the United States would be adequate for the purposes of Japanese and Western European paper manufacturers.

(C) Paper manufacturers in Japan and Western Europe would prefer to use wood pulp produced in the United States if cost were not a factor.

(D) Demand for paper products made in Japan and Western Europe will not increase sharply during this year.

(E) Production of wood pulp by United States companies will not increase sharply during this year.

The proposal to hire ten new police officers in Middletown is quite foolish. There is sufficient funding to pay the salaries of the new officers, but not the salaries of additional court and prison employees to process the increased caseload of arrests and convictions that new officers usually generate.

Which of the following, if true, will most seriously weaken the conclusion drawn above?

(A) Studies have shown that an increase in a city’s police force does not necessarily reduce crime.

(B) When one major city increased its police force by 19 percent last year, there were 40 percent more arrests and 13 percent more convictions.

(C) If funding for the new police officers’ salaries is approved, support for other city services will have to be reduced during the next fiscal year.

(D) In most United States cities, not all arrests result in convictions, and not all convictions result in prison terms.

(E) Middletown’s ratio of police officers to citizens has reached a level at which an increase in the number of officers will have a deterrent effect on crime.

A researcher discovered that people who have low levels of immune-system activity tend to score much lower on tests of mental health than do people with normal or high immune-system activity. The researcher concluded from this experiment that the immune system protects against mental illness as well as against physical disease.

The researcher’s conclusion depends on which of the following assumptions?

(A) High immune-system activity protects against mental illness better than normal immune-system activity does.
(B) Mental illness is similar to physical disease in its effects on body system.
(C) People with high immune-system activity cannot develop mental illness.
(D) Mental illness does not cause people’s immune-system activity to decrease.
(E) Psychological treatment of mental illness is not as effective as is medical treatment.

Seven countries signed a treaty binding each of them to perform specified actions on a certain fixed date, with the actions of each conditional on simultaneous action taken by the other countries. Each country was also to notify the six other countries when it had completed its action.

The simultaneous-action provision of the treaty leaves open the possibility that

(A) the compliance date was subject to postponement, according to the terms of the treaty

(B) one of the countries might not be required to make any changes or take any steps in order to comply with the treaty, whereas all the other countries are so required

(C) each country might have a well-founded excuse, based on the provision, for its own lack of compliance

(D) the treaty specified that the signal for one of the countries to initiate action was notification by the other countries that they had completed action

(E) there was ambiguity with respect to the date after which all actions contemplated in the treaty are to be complete

There are two boxes of markers. The first box has only red, orange and yellow markers. The second box has only yellow, green and blue markers. If a marker is chosen at random from each of the boxes, is the probability that both markers will be yellow less than 30%?

(1) Four of the 12 total markers are yellow

(2) The probability of selecting a red or orange marker is 3/5 and the probability of selecting a green or blue marker is 2/7

A) Statement (1) alone is sufficient, but statement (2) alone is not sufficient

B) Statement (2) alone is sufficient, but statement (1) alone is not sufficient

C) Both statements together are sufficient, but neither statement alone is sufficient

D) Each statement alone is sufficient

E) Statement (1) and (2) together are not sufficient

Meteorologists say that if only they could design an accurate mathematical model of the atmosphere with all its complexities, they could forecast the weather with real precision. But this is an idle boast, immune to any evaluation, for any inadequate weather forecast would obviously be blamed on imperfections in the model.

Which of the following, if true, could best be used as a basis for arguing against the author’s position that the meteorologists’ claim cannot be evaluated?

(A) Certain unusual configurations of data can serve as the basis for precise weather forecasts even though the exact causal mechanisms are not understood.

(B) Most significant gains in the accuracy of the relevant mathematical models are accompanied by clear gains in the precision of weather forecasts.

(C) Mathematical models of the meteorological aftermath of such catastrophic events as volcanic eruptions are beginning to be constructed.

(D) Modern weather forecasts for as much as a full day ahead are broadly correct about 80 percent of the time

(E) Meteorologists readily concede that the accurate mathematical model they are talking about is not now in their power to construct.

By showing that South Africa does not have a free market and is in fact a kind of collectivist welfare state for Whites only, Sowell argues that American conservatives have no valid ideological grounds to be in sympathy with the Pretoria regime.

(A) to be in sympathy with

(B) to sympathize with

(C) for sympathizing with

(D) that they should sympathize with

(E) that they should have sympathy for

As the housing affordability gap widens, middle-income families are especially hard-hit, and these families can no longer qualify to buy homes, and rising rental rates force them to use far more than the standard 25 percent of their incomes for housing, leaving them with no equity or tax write-offs to offset the expenditures.

(A) and these families can no longer qualify to buy homes, and

(B) since these families can no longer afford to buy homes, furthermore

(C) for these families can no longer afford to buy homes, yet

(D) and these families can no longer afford to buy homes; however,

(E) and these families can no longer afford to buy homes, for