Well, in order for a clinical trial to generate valid and widely applicable results, they need to be conducted with large numbers of study participants and preferably on a population with a high incidence of new HIV infections.
为了让临床实验获得 人数和复盖率过多而有令人信服的结果 大量的病人会被招募参与实验 这些病人都优先从 艾滋病新感染率很高的地区找来的