Question

13．US scientists have performed an important reversal（逆轉） of the ageing process in animal studies．They used a chemical to rejuvenate（使年輕） muscle in mice and said it was the equivalent（等同于） of transforming a 60-year-old's muscle to that of a 20-year-old-but muscle strength did not improve．Their study，in the journal Cell，identified an entirely new mechanism（原理） of ageing and then reversed it．Other researchers said it was an"exciting finding"．
Ageing is considered a one-way street，but now researchers at Harvard Medical School have shown that some aspects can be reversed．Their research focused on a chemical called NAD．Its levels naturally drop in all cells of the body with age．The team showed this damaged the function of the cell's in-built power-stations，leading to lower energy production and ageing．
Experiments showed that increasing NAD levels，by giving mice a chemical which they naturally change into NAD，could reverse the sands of time．One week of youth-medication in two-year-old mice meant their muscles became similar to those of a six-month-old．
Dr Ana Gomes，from the department of genetics at Harvard Medical School，said："We believe this is quite an important finding．"She argues muscle strength may return with a longer course of treatment．However，this could never be a cure-all for ageing．Other aspects such as shortening of telomeres or damage to DNA would not be reversed．
Dr Gomes told the BBC："Ageing is multi-factorial，it's not just one component（成分） we can fix，so it's hard to target the whole thing．I believe there is a lot of cross-talk in cells and energy is very important in a cell and likely to be a very big component of ageing that might cause some of the other things that happen with ageing．"
68．From paragraph 1 we learn thatD．
A．bones can be transformed
B．muscle strength can be transformed
C．color can be transformed
D．muscle can be transformed
69．From paragraph 2 and paragraph 3 we learn thatC
A．researchers think ageing is a one-way street．
B．NAD levels'dropping could make mice become younger．
C．increasing NAD levels could make mice become younger．
D．researchers think any aspect can be reversed．
70．Dr Gomes will agree thatB
A．we can target everything about ageing．
B．muscle strength may return over a longer course of treatment．
C．a(chǎn)geing could be cured．
D．energy is of little importance in a cell．

Answer 1

分析 本文是一篇科教類閱讀，主要講的是一個令人振奮的"可以逆轉老化過程"的發(fā)現(xiàn)．

解答 68-70．DCB
68題答案：D考查細節(jié)推理，根據(jù)第一段的They used a chemical to rejuvenate（使年輕） muscle in mice and said it was the equivalent（等同于） of transforming a 60-year-old's muscle to that of a 20-year-old-but muscle strength did not improve．（他們使用一種化學物質來使老鼠的肌肉年輕化并且說這等同于將60歲老人的肌肉變成20歲年輕人肌肉--但是肌肉的力量沒有提高）．可知本題答案為D選項．
69題答案：C考查細節(jié)推理，根據(jù)第三段的Experiments showed that increasing NAD levels…could reverse the sands of time．試驗表明增加NAD的等級可以逆轉時間．可知提高NAD的等級可以是老鼠變年輕，故本題答案為C選項．
70題答案：B考查細節(jié)推理，根據(jù)文章倒數(shù)第二段的She argues muscle strength may return with a longer course of treatment．她提出理由證明肌肉的力量在長期的治療后可以恢復．可知本題答案為B選項．

點評 本文是一篇科教類閱讀，題目涉及多道細節(jié)理解題，做題時結合原文和題目有針對 性找出相關語句進行仔細分析，結合選項選出正確答案．推理判斷也是要在抓住關鍵句子的基礎上合理的分析才能得出正確的答案．