Martha' s friend, who is very knowledgeable about edible flowers, told Martha that there are no edible daisies, at least not any that are palatable
Martha, however, reasons that since there are daisies that are a kind of chrysanthemum and since there are edible chrysanthemums that are quite palatable, what her friend told her must be incorrect
Some of Noriko's sisters are on the debate team, and some members of the debate team are poor students. So at least one of Noriko's sisters must be a poor student.