2012年12月大学英语六级阅读专项练习题14

47．If the drug proves effective in human trials，it could enhance the effectiveness of existing AIDS drugs in___________________.
48．What has become standard cocktail therapy? 考试用书
49．While integrase deletes an immune cell’s genetic material and replaces it with its own，it acts like_____________in a word processor．
50．Why would anti-AIDS drugs stop working?
51．According to Steven Young，if scientists get the data that_______，they would petition for fast track status．