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The nuclear polyhedrosis virus helps control gypsy moth populations by killing the moth’s larvae. The virus is always present in the larvae, but only every sixth or seventh year does the virus seriously decimate the number of larvae, thereby drastically setting back the gypsy moth population. Scientists believe that the virus, ordinarily latent, is triggered only when the larvae experience biological stress. If the scientists mentioned above are correct, it can be inferred that the decimation of gypsy moth larvae populations by the nuclear polyhedrosis virus would be most likely to be triggered by which of the following conditions

A shift from drought conditions to normal precipitation in areas infested by gypsy moths.
B. The escalating stress of defoliation sustained by trees at tacked by gypsy moths for the second consecutive year.
C. Predation on larvae of all kinds by parasitic wasps and flies.
D. Starvation of the gypsy moth larvae as a result of overpopulation.
E. (E) Spraying of areas infested by gypsy moths with laboratory-raised nuclear polyhedrosis virus.

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Unless negotiations begin soon, the cease-fire will be violated by one of the two sides to the dispute. Negotiations will be held only if other countries have pressured the two sides to negotiate; an agreement will emerge only if other countries continue such pressure throughout the negotiations. But no negotiations will be held until international troops enforcing the cease-fire have demonstrated their ability to counter any aggression from either side, thus suppressing a major incentive for the two sides to resume fighting. If the statements above are true, and if negotiations between the two sides do begin soon, at the time those negotiations begin each of the following must also be true EXCEPT:

A. The cease-fire has not been violated by either of the two sides.
B. International troops enforcing the cease-fire have demonstrated that they can counter aggression from either of the two sides.
C. A major incentive for the two sides to resume hostilities has been suppressed.
D. Other countries have exerted pressure on the two sides to the dispute.
E. (E) The negotiations’ reaching an agreement depends in part on the actions of other countries.

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The fire that destroyed the Municipal Building started before dawn this morning, and the last fire fighters did not leave until late this afternoon. No one could have been anywhere in the vicinity of a fire like that one and fail to notice it. Thomas must have seen it, whatever he now says to the contrary. He admits that, as usual, he went from his apartment to the library this morning, and there is no way for him to get from his apartment to the library without going past the Municipal Building. The main conclusion of the argument is that

A. Thomas was in the vicinity of the fire this morning.
B. Thomas claimed not to have seem the fire.
C. Thomas saw the fire this morning.
D. Thomas went directly from his apartment to the library this morning.
E. (E) Thomas went by the Municipal Building this morning.

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Forty-five percent of all blood donated in the United States is type O. Type O blood is essential for emergencies where there is no time for determining the blood type of victims because type O blood can be used for everyone. Type O blood is unique in that it is compatible with blood of all types: any recipient, regardless of blood type, can be given it. But precisely because of this special usefulness, type O blood is chronically in short supply. If the statements in the passage above are true, which of the following must also be true

A. The special usefulness of type O blood lies in the fact that it matches the blood type of most people.
B. Supplies of type O blood are continuously so low that type O blood is unavailable for emergencies, where its usefulness would be greatest.
C. Forty-five percent of the total population of the United State has type O blood, which makes type O the most common blood type.
D. Any decision to give blood of any type other than O needs to be based on knowledge of the recipient’s blood type.
E. (E) Type O blood is the only blood that cannot be typed as fast as needed in emergencies.

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Some of the world’s most beautiful cats are Persian cats. However, it must be acknowledged that all Persian cats are pompous, and pompous cats are invariably irritating. If the statements above are true, each of the following must also be true on the basis of them EXCEPT:

A. Some of the world’s most beautiful cats are irritating.
B. Some irritating cats are among the world’s most beautiful cats.
C. Any cat that is not irritating is not a Persian cat.
D. Some pompous cats are among the world’s most beautiful cats.
E. (E) Some irritating and beautiful cats are not Persian cats.

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