21.If T is assigned to the same class as V, which of the

　　following must be assigned to the same class as each

　　other?

　　(A) R and T

　　(B) S and X

　　(C) S and Y

　　(D) X and Y

　　(E) Y and Z

　　22.If V is assigned to a different class from Z, which of

　　the following must be true?

　　(A) S is assigned to Class 1.

　　(B) S is assigned to Class 2.

　　(C) T is assigned to Class 2.

　　(D) V is assigned to Class 2.

　　(E) X is assigned to Class 1.

　　23 Politician：Each year, small businesses create more

　　jobs than do large established businesses.

　　Therefore, in order to reduce unemploy-

　　ment in the long term, we should provide

　　incentives for starting small businesses

　　rather than for expanding established large

　　businesses.

　　Which of the following, if true, casts the most doubt

　　on the politician’s argument?

　　(A) In general, people employed by small businesses

　　report higher job satisfaction than do people

　　employed by large businesses.

　　(B) Among the currently unemployed are many

　　people with sufficient job skills to perform the

　　jobs that small businesses would create.

　　(C) Providing an effective incentive for starting a

　　business generally costs significantly less than

　　providing an effective incentive for expanding

　　a large business.

　　(D) A high proportion of small businesses fail within

　　three years of starting because of their owners’

　　inexperience.

　　(E) The average large business contributes more

　　money to politicians’ campaign funds than the

　　average small business does.

　　24 In the workplace, influenza is typically spread by

　　infected individuals to others with whom they work

　　in close quarters. A new medication that suppresses

　　the symptoms of influenza therefore will actually

　　increase the number of influenza cases, because this

　　medication will allow people who would otherwise be

　　home in bed to return to work while infected.

　　Which of the following, if true, most seriously chal-

　　lenges the prediction?

　　(A) Coughing, a symptom of influenza that the new

　　medication suppresses, is a primary mechanism

　　in the spread of this illness.

　　(B) Some medications that are used to suppress

　　symptoms of influenza are also used by many

　　people to treat symptoms that are caused not

　　by influenza but by other illnesses.

　　(C) Many workers who now remain at home when

　　infected with influenza do so because the

　　symptoms of influenza prevent them from per-

　　forming their jobs effectively.

　　(D) Most adults who are immunized against influ-

　　enza in order to avoid being infected are over

　　65 years old and retired and thus do not work

　　outside the home.

　　(E) Symptoms of an illness are often the body’s

　　means of curing itself of the illness, and there-

　　fore suppression of symptoms can prolong the

　　illness that causes them.

　　25 Editorial：

　　Critics of nuclear power complain about the allegedly

　　serious harm that might result from continued operation

　　of existing nuclear power plants. But such concerns do

　　not justify closing these plants;after all, their operation

　　has caused no more harm than that caused by pollution

　　generated by coal-and oil-burning power plants, the

　　most important other sources of energy.

　　Which of the following is an assumption on which the

　　argument depends?

　　(A) Existing nuclear power plants should be closed only

　　if it can be conclusively demonstrated that their

　　continued operation is likely to cause harm more

　　serious than the harm their operation has already

　　caused.

　　(B) Closing existing nuclear power plants would require

　　greatly increased reliance on coal-and oil-burning

　　power plants.

　　(C) The harm that has resulted from operation of

　　existing coal-and oil-burning power plants has

　　been significant.

　　(D) The harm that a nuclear power plant is likely to

　　cause as it continues to operate can be reliably

　　predicted from the past history of nuclear power

　　plants.

　　(E) The only harm that has resulted from operation of

　　existing coal-and oil-burning power plants has

　　resulted from the pollution generated by these

　　plants.