Historian: We can learn about the medical history of individuals through chemical analysis of their hair. It is likely, for example, that Isaac Newton’s psychological problems were due to mercury poisoning; traces of mercury were found in his hair. Analysis is now being done on a lock of Beethoven’s hair. Although no convincing argument has shown that Beethoven ever had a venereal disease, some people hypothesize that venereal disease caused his deafness. Since mercury was commonly ingested in Beethoven’s time to treat venereal disease, if researchers find a trace of mercury in his hair, we can conclude that this hypothesis is correct. Which one of the following is an assumption on which the historian’s argument depends? (A) None of the mercury introduced into the body can be eliminated. (B) Some people in Beethoven’s time did not ingest mercury. (C) Mercury is an effective treatment for venereal disease. (D) Mercury poisoning can cause deafness in people with venereal disease. (E) Beethoven suffered from psychological problems of the same severity as Newton’s.
On a certain day, nine scheduled flights on Swift Airlines were canceled. Ordinarily, a cancellation is due to mechanical problems with the airplane scheduled for a certain flight. However, since it is unlikely that Swift would have the mechanical problems with more than one or two scheduled flights on a single day, some of the nine cancellations were probably due to something else. The argument depends on which one of the following assumptions? (A) More than one or two airplanes were scheduled for the nine canceled flights. (B) Swift Airlines has fewer mechanical problems than do other airlines of the same size. (C) Each of the canceled flights would have been longer than the average flight on Swift Airlines. (D) Swift Airlines had never before canceled more than one or two scheduled flights on a single day. (E) All of the airplanes scheduled for the canceled flights are based at the same airport.
Ordinary mountain sickness, a common condition among mountain climbers, and one from which most people can recover, is caused by the characteristic shortage of oxygen in the atmosphere at high altitudes. Cerebral edema, a rarer disruption of blood circulation in the brain that quickly becomes life-threatening if not correctly treated from its onset, can also be caused by a shortage of oxygen. Since the symptoms of cerebral edema resemble those of ordinary mountain sickness, cerebral edema is especially dangerous at high altitudes. Which one of the following is an assumption on which the argument depends? (A) The treatment for ordinary mountain sickness differs from the treatment for cerebral edema. (B) Cerebral edema can cause those who suffer from it to slip into a coma within a few hours. (C) Unlike cerebral edema, ordinary mountain sickness involves no disruption of blood circulation in the brain. (D) Shortage of oxygen at extremely high altitude is likely to affect thinking processes and cause errors of judgment. (E) Most people who suffer from ordinary mountain sickness recover without any special treatment.