【求助大牛】feifei逻辑61

Jessie609

这道题的问题里，underlying是削弱的意思么？为什么所有的答案解释都在找削弱argument的选项？ undermine不才是"削弱"吗？求解释

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.

greygray

这个查字典就可以了吧。。。。underlying是underlie的进行时态，作为。。。的基础的意思