22. Virginia and her brother William disagree over when their father was born： Virginia claims it was in 1935 and William claims it was in 1933. The hospital where their father was born has no records for 1933 but has complete records for 1935—records that do not include a birth record for their father. Therefore，he must have been born in 1933.
The argument depends on which of the following assumptions?
(A) Either Virginia's claim or William's claim is correct.
(B) The records of the hospital where their father was born date back to 1933.
(C) Virginia and William know the day and the month of their father's birth.
(D) There are urgent practical reasons why Virginia and William must know the date of their father's birth.
(E) None of their other relatives knows the year in which Virginia and William's father was born.
23. The town of San Leonardo has recently enacted a law banning smoking in all restaurants within town limits.Since many smokers who normally dine in San Leonardo's restaurants will not want to refrain from smoking during their meals， San Leonardo's restau-rants will undoubtedly lose many patrons and con-siderable income.
Which of the following， if true， most helps to strengthen the argument above?
(A) Most residents of San Leonardo who eat in res-taurants are not smokers.
(B) Most smokers who dine in the company of non-smokers are willing to refrain from smoking during their meals.
(C) If the law banning smoking in restaurants had not been enacted， it is likely that a more stringent law banning smoking in all public places in San Leonardo would have been enacted instead.
(D) Prior to the enactment of the law banning smoking in San Leonardo's restaurant， the town had a law that required most restaurants to have nonsmoking sections.
(E) None of the other communities adjacent to San Leonardo， which have restaurants comparable to those of San Leonardo， has enacted and enforces any antismoking legislation.
24. Children whose biological parents both have Tic Syndrome Z (TSZ)， which is characterized by the involuntary contraction of certain muscles， are about four times more likely to develop such contractions than are children whose biological parents do not have TSZ， It is likely， therefore， that predisposition to TSZ is an inherited trait.
Which of the following， if true， would most strengthen the conclusion above?
(A) Children whose parents have TSZ are more likely to develop TSZ if they are under unusual stress at school or at home than if they are not under such stress.
(B) Children whose biological parents do not have TSZ are more likely to develop TSZ if they are raised by adoptive parents with TSZ than if they are raised by their biological parents.
(C) Children whose biological parents have TSZ are as likely to develop TSZ if they are raised by adoptive parents who do not have TSZ as if they are raised by their biological parents.
(D) Children whose biological parents have TSZ and who develop TSZ usually avoid developing a severe form of the syndrome if they seek treatment for TSZ shortly after developing the first signs of it.
(E) Children with TSZ whose biological parents do not have TSZ are less likely to have the syn-drome diagnosed when symptoms first appear than are children with TSZ whose biological parents have TSZ.
25. Playing eighteenth-century music on the instruments of that period provides valuable information about how the music originally sounded. Eighteenth-century instruments cannot be played without being restored， however， and restoring such an instrument destroys all of the information that researchers could obtain from it about eighteenth-century instrument-making techniques.
If the statements above are true， which of the following must be true on the basis of them?
(A) Eighteenth-century instruments cannot be used to provide information about the original techniques used in playing such instruments if they have been restored.
(B) Eighteenth-century instruments that have been restored can provide information only about how eighteenth-century music originally sounded
(C) Eighteenth-century instruments are the only source of information about the instrument-making techniques of that period.
(D) An eighteenth-century instrument that has not been restored can provide more information than can one that has been restored.
(E) An eighteenth-century instrument cannot serve as a source of new information about eighteenth-century instrument-making techniques once it can be played.
参考答案： 22.A 23.E 24.C 25.E