11.In malaria-infested areas, many children tend to suffer several bouts of malaria before becoming immune to the disease. Clearly, what must be happening is that those children’s immune systems are only weakly stimulated by any single exposure to the malaria parasite and need to be challenged several times to produce an effective immune response.

  Which of the following, if true, most seriously undermines the explanatory hypothesis?

  (A) Immediately after a child has suffered a bout of malaria, the child’s caregivers tend to go to great lengths in taking precautions to prevent another infection, but this level of attention is not sustained.

  (B) Malaria is spread from person to person by mosquitoes, and mosquitoes have become increasingly resistant to the pesticides used to control them.

  (C) A certain gene, if inherited by children from only one of their parents, can render those children largely immune to infection with malaria.

  (D) Antimalaria vaccines, of which several are in development, are all designed to work by stimulating the body’s immune system.

  (E) There are several distinct strains of malaria, and the body’s immune response to any one of them does not protect it against the others.

  12.An advertisement designed to convince readers of the great durability of automobiles manufactured by the Deluxe Motor Car Company cites as evidence the fact that over half of all automobiles built by the company since 1970 are still on the road today, compared to no more than a third for any other manufacturer.

  Which of the following, if true, most strongly supports the advertisement’s argument?

  (A) After taking inflation into account, a new Deluxe automobile costs only slightly more than a new model did in 1970.

  (B) The number of automobiles built by Deluxe each year has not increased sharply since 1970.

  (C) Owners of Deluxe automobiles typically keep their cars well maintained.

  (D) Since 1970, Deluxe has made fewer changes in the automobiles it manufactures than other car companies have made in their automobiles.

  (E) Deluxe automobiles have been selling at relatively stable prices in recent years.

  13.Many state legislatures are considering proposals to the effect that certain policies should be determined not by the legislature itself but by public referenda in which every voter can take part. Critics of the proposals argue that the outcomes of public referenda would be biased, since wealthy special-interest groups are able to influence voters’ views by means of television advertisements.

  Which of the following, if true, most strengthens the critics’ argument?

  (A) Many state legislators regard public referenda as a way of avoiding voting on issues on which their constituents are divided.

  (B) During elections for members of the legislature, the number of people who vote is unaffected by whether the candidates run television advertisements or not.

  (C) Proponents of policies that are opposed by wealthy special-interest groups are often unable to afford advertising time on local television stations.

  (D) Different special-interest groups often take opposing positions on questions of which policies the state should adopt.

  (E) Television stations are reluctant to become associated with any one political opinion, for fear of losing viewers who do not share that opinion.

  14.Advertisement: Of the many over-the-counter medications marketed for the relief of sinus headache. SineEase costs the least per dose. And SineEase is as effective per dose as the most effective of those other medications. So for relief from sinus headaches, SineEase is the best buy.

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

  (A) Most of the over-the-counter medications marketed for the relief of sinus headache are equally effective per dose in providing such relief.

  (B) Many of the over-the-counter medications marketed for the relief of sinus headache contain the same active ingredient as SineEase.

  (C) People who suffer from frequent sinus headaches are strongly advised to consult a doctor before taking any over-the-counter medication.

  (D) An over-the-counter medication that is marketed for the relief of symptoms of head cold is identical in composition to SineEase but costs less per dose.

  (E) The per dose price for any given over-the-counter medication marketed for the relief of sinus headache is higher for smaller packages than it is for larger packages.

  15.In the United States, vacationers account for more than half of all visitors to what are technically called “pure aquariums” but for fewer than one quarter of all visitors to zoos, which usually include a “zoo aquarium” of relatively modest scope.

  Which of the following, if true, most helps to account for the difference described above between visitors to zoos and visitors to pure aquariums?

  (A) In cities that have both a zoo and a pure aquarium, local residents are twice as likely to visit the aquarium as they are to visit the zoo.

  (B) Virtually all large metropolitan areas have zoos, whereas only a few large metropolitan areas have pure aquariums.

  (C) Over the last ten years, newly constructed pure aquariums have outnumbered newly established zoos by a factor of two to one.

  (D) People who visit a zoo in a given year are two times more likely to visit a pure aquarium that year than are people who do not visit a zoo.

  (E) The zoo aquariums of zoos that are in the same city as a pure aquarium tend to be smaller than the aquariums of zoos that have no pure aquarium nearby.

  16.Which of the following, if true, is the most logical completion of the argument below?

  The tax system of the Republic of Grootland encourages borrowing by granting its taxpayers tax relief for interest paid on loans. The system also discourages saving by taxing any interest earned on savings. Nevertheless, it is clear that Grootland’s tax system does not consistently favor borrowing over saving, for if it did, there would be no______

  (A) tax relief in Grootland for those portions of a taxpayer’s income, if any, that are set aside to increase that taxpayer’s total savings

  (B) tax relief in Grootland for the processing fees that taxpayers pay to lending institutions when obtaining certain kinds of loans

  (C) tax relief in Grootland for interest that taxpayers are charged on the unpaid balance in credit card accounts

  (D) taxes due in Grootland on the cash value of gifts received by taxpayers from banks trying to encourage people to open savings accounts

  (E) taxes due in Grootland on the amount that a taxpayer has invested in interest-bearing savings accounts