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【疾病健康类/饮食类】话题阅读练习题 高频话题 01 疾病健康类passage 1a us man has become the first person in the world to receive a heart transplant from a geneticallymodified pig.surgeons say the experimental procedures was the only available option for the patient david bennett,a 57-year-old from maryland in the us, who was living with heart disease.bennett is currently being carefully monitored while specialists at the university of marylandmedical center, where the procedure was carried out, determine whether the transplant can keep him alivein the long term. “it was either to die, or do this transplant. i want to live. i know it’s a shot in the dark, butit’s my last choice,” said bennett. “i look forward to getting out of bed after i recover.”while full heart transplants are more controversial, pig heart valves (瓣膜) have been successfullyused for replacements in humans for years.“this was a breakthrough surgery and brings us one step closer to solving the organ shortage crisis.there are simply not enough donor human hearts available to meet the long list of potential recipients,”said bartley griffith, the heart surgeon who performed the operation. “we are doing cautiously, but we arealso optimistic that this first-in-the-world surgery will provide an important new option for patients in thefuture.”in the donor pig, three genes that would have led to the repaid rejection of the pig’s heart wereknocked out. six human genes responsible for immune acceptance of the pig heart were then inserted intothe genome. finally, one gene in the pig was removed to prevent excessive growth of the heart tissue onceit had been implanted.“this is truly a historic, monumental step forward. while we have long been at the forefront ofresearch driving progress toward the promise of xenotransplantation (异种器官移植) as a practicalsolution to the organ crisis, many believed this breakthrough would be well into the future,” said berto’malley, president and ceo of the university of maryland medical center.1．why did david bennett have heart transplant surgery?a．because it is the last way for him to survive.b．because he is the volunteer of the experiment.