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?
49.While integrase deletes an immune cells 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.