FF70求解

iceberg07

70. A low-pressure weather system is approaching Plainville; rainfall results from about 70 percent of such systems in the Plainville area. Moreover, the current season, spring, is the time of year in which thundershowers, which sometimes result from low-pressure systems, are most likely to occur in Plainville.
Knowing which one of the following, in addition to the information above, would be most useful for determine the probability that Plainville will have a thundershower soon?
(A) the percentage of thundershowers in Plainville that occur in the spring
(B) the percentage of spring rainfalls in Plainville that are thundershowers
(C) the percentage of thundershowers in Plainville that result from low-pressure systems
(D) whether low-pressure systems in other areas are associated with rainfall
(E) whether Plainville has more or fewer thundershowers each spring than do near by towns

                           
答案是B，但是详解版的答案是C。 我选的也是C。求做过的同学确认一下答案，多谢。

iceberg07

弱问一下，不能删贴嘛？发了之后翻以前的帖子发现有人讨论过了，想删贴没找到，汗！