"Yeah, I really think that's what we're hoping for," he said. "I mean, we need to get data that show it has robust anti-viral effects in people. And if we're able to get that data, I think we would petition for fast track status."

　　Dr. Young says an integrase inhibitor has the potential to prevent drug resistance.

　　"To ensure our best chance of preventing resistance, we would give this as part of a cocktail therapy," he added. "And I think it's really our plan that we would test this with reverse transcriptase inhibitors and protease inhibitors, as well."

　　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 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.

　　Section B

　　Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked [A], [B], [C] and [D]. You should decide on the best choice and mark the corresponding letter on Answer Sheet 2 with a single line through the center.

　　Passage One

　　Questions 52 to 56 are based on the following passage.

　　Occasional self-medication has always been part of normal living. The making and selling of drugs have a long history and are closely linked, like medical practice itself, with the belief in magic. Only during the last hundred years or so has the development of scientific techniques made it possible for some of the causes of symptoms to be understood, so that more accurate diagnosis has become possible. The doctor is now able to follow up the correct diagnosis of many illnesses with specific treatment of their causes. In many other illnesses, of which the causes remain unknown, it is still limited, like the unqualified prescriber, to the treatment of symptoms. The doctor is trained to decide when to treat symptoms only and when to attack the cause: this is the essential difference between medical prescribing and self-medication.

　　The advance of technology has brought about much progress in some fields of medicine, including the development of scientific drug therapy. In many countries public health organization is improving and people's nutritional standards have risen. Parallel with such beneficial trends have two adverse effects. One is the use of high-pressure advertising by the pharmaceutical industry, which has tended to influence both patients and doctors and has led to the overuse of drugs generally. The other is the emergence of the sedentary society with its faulty ways of life: lack of exercise, over-eating, unsuitable eating, insufficient sleep, excessive smoking and drinking. People with disorders arising from faulty habits such as these, as well as from unhappy human relationships, often resort to self-medication and so add the taking of pharmaceuticals to the list. Advertisers go to great lengths to catch this market.