61. Investigators concluded that human failure was not responsible for the fatal airplane crash last August, and since that time new and more stringent rules for identifying and reporting mechanical problems have been in effect. That accounts for the fact that reports of airplane mechanical problems have increased in frequency by 50 percent since last August. Which one of the following is an assumption underlying the argument in the passage? (A) Airplane travel is still relatively safe, despite the increase in reported mechanical problems. (B) Mechanical problems in airplanes have increased dramatically since last August. (C) Mechanical problems in airplanes have not increased by 50 percent since last August. (D) Airlines are less reluctant to report mechanical problems than they previously were. (E) Mechanical problems in airplanes have become easier to detect since last August.
答案C。Mechanical problems in airplanes have not increased by 50 percent since last August。机械问题自八月以来没有增加50%。(实际情况)。 That accounts for the fact that reports of airplane mechanical problems have increased in frequency by 50 percent since last August。报告的机械问题自八月以来增加50%。(报告情况)。实际情况小于报告情况,所以才能推出new and more stringent rules for identifying and reporting mechanical 。同时保证结论成立。