14 The average modified mouse lived
A 3 years.
B 753 days.
C More than 3 years.
D 887 days.
15 What can be inferred from the passage about the route to long life?
A It remains to be studied.
B It has already been discovered.
C Eating more leads to long life.
D Eating less leads to long life.
答案：11. C 12. B 13. A 14. D 15. A
解析：
11. C 细节题，这里的定位词可以是Ronald Kahn and his colleagues和mice，在原文中找到 Ronald Kahn at Harvard Medical School in Boston， US， and his colleagues have been able to extend the lifespan (寿命) of mice by 18 per cent by blocking the rodents (啮齿动物) increase of fat in specific cells.其中extend the lifespan (寿命) of mice是延长老鼠寿命的意思。这里的by blocking the rodents...是by引导的方式状语从句。答案就在此。这里的fat in specific cells恰好对应了选项C的specific genes in their fat cells.
12. B 细节题，关于human的叙述在Whether this works in humans is still unknown， partly because few people are willing to submit to such a strict diet.所以选B.
13. A 推断题，因为这里有imply暗示。在原文中找到相应句子，"These mice eat all they want， lose weight and live longer. Its like heaven."这句话没有生词，我们可以将其翻译出来：这些老鼠们吃他们想吃的，还减肥并且还长寿，这简直就是天堂！将选项都可以翻译出来，发现只有A 合适。这句话言外之意就是人们减肥但是又不想少吃。所以mice的这种情况被认为是天堂。
14. D 细节题，关键词是average modified mouse，在原文找到The average control mouse lived 753 days， while the thin rodents averaged a lifespan of 887 days.这里的改良的mouse就是指比较瘦的，所以这里选887days
15. A 推断题，关于走向长寿的路径，属于总结性的意思，在最后一段话中It might be the same effect or there might be two routes to long life，" he points out， "and that would be very interesting."这里作者都与effect和routes都用了might一词，说明还不确定这种效果能不能在人身上体现，所以选项A有待研究比较符合题意。