标题: 请教一道LR [打印本页] 作者: 青花栈 时间: 2010-5-4 07:52 标题: 请教一道LR Biologist: We know the following things about Plant X. Specimens with fuzzy seeds always have long stems but never have white flowers. Specimens with curled leaves always have white flowers, and specimens with thorny seedpods always have curled leaves. A specimen of plant X in my garden has a long stem and curled leaves.
From the biologist's statements, which one of the following can be properly inferred about the specimen of plant X in the biologist's garden?
A. It has white flowers and thorny seedpods. B. It has white flowers but lacks thorny seedpods. C. It has white flowers but lacks fuzzy seeds. D. It has fuzzy seeds and thorny seedpods. E. It lacks both white flowers and fuzzy seeds.
Answer is C作者: fjatpku 时间: 2010-5-4 10:45
1: fuzzy seeds => long stems & no white flowers 2: curled leaves => white flowers
plant X: curled leaves => white flowers => no fuzzy seeds (contrapositive of 1) Thus C is correct.作者: 青花栈 时间: 2010-5-8 05:35
thank you very much!
