原文的推理: Telomerase is produced only in actively dividing cells. Bone marrow cells continually divide ---->Telomerase is produced in Bone marrow cells. Cancer cells are rapidly dividing ----->Telomeras is also produced in cancer cells. 选项B: 小孩身上唯一没有Telomeras的tissue是那些细胞没在rapidly divide的tissue. 这里需要区分 actively divide和rapidly divide, actively divide不一定是rapidly divide, 但rapidly divide一定是actively divide. 也就是rapidly divide的范围要小。 所以b应该说成:In children, the only body tissues from which telomerase is absent are those in which cells are not actively dividing. 选项C: 骨髓细胞中出现Telomerase 并不表明已患上骨髓癌。 正确。 因为出现在骨髓细胞中的Telomerase有两个可能的来源:1. 癌细胞分裂 2.骨髓细胞本身分裂 -- by 会员 ctkstarcraft (2010/2/25 15:00:27)
谢谢ctkstarcraft~不过我还是有点困惑该题充要性的问题,我也有注意到B的概念偷换,但如果就算B改成actively,我想清楚一下,这确实是原文的否命题,对吗?不过我记得新东方老师说了,support类的归纳题是可以出现否命题的,所以如果B改成了actively就可以算对,是吧? |