131. To become an expert on a musical instrument, a person must practice. If a person practice a musical instrument for three hours each day, they will eventually become expert on that instrument. Therefore, if a person is an expert on a musical instrument, that person must have practiced for at least three hours each day.

Which one of the following most accurately describes a flaw in the reasoning above?

A.        The conclusion fails to take into account that people who practice for three hours every day might not yet have reached a degree of proficiency that everyone would consider expert.

B.        The conclusion fails to take into account that practicing for less than three hours each day may be enough for some people to become experts.

C.        the conclusion fails to take into account that if a person has not practiced for at least three hours a day, the person has not become an expert.

D.       The conclusion fails to take into account that three consecutive hours of daily practice is not recommended by all music teachers.

E.        The conclusion fails to take into account that few people have the spare time necessary to devote three hours daily to practice.

答案是B，求NN给一下思路，谢谢拉！！

归纳性的推理是由个别性的前提推到一般性的结论，其结论是或然性的

所以说有些人一天练3小时可以成为专家，有些人可能只用一小时也足以成为专家。选B

就是说三个小时非充分必要条件。