问题
单项选择题
Question 5 is based on the following graph.
Drug X, which kills on contact the bacteria that cause the infection, is administered to patients by means of an aerosol inhaler.
Which of the following, if true, contributes most to explaining the change in drug X’s effectiveness during the course of the infection
答案
参考答案：D
解析： 本题为解释图表题，重在抓住图表的变化点。(D)指出受感染的病人在第二周吸入药的能力受到损害，解释了第二周以后图的变化，因此(D)正确；(A)解释不了图的变化；(B)中病人的愿望与药的疗效无关；(C)易误选，但每周使用剂量的增加并无法解释上图中第二周后，图线下降趋缓的事实，所以(C)不对；(E)无关。