OG9 阅读 Q52

Choice D is the best answer. The previous question asks which conclusion about the mice in the experiment described in Passage 1 is best supported by information in Passage 2. The answer, that their upper respiratory tract infections were likely not caused by gram-negative bacteria, is best supported by the fourth sentence of the third paragraph of Passage 2: "[Teixobactin] doesn't kill the Gram-negative opportunists as it is too big to cross their complex cell wall."
Choices A, B, and C are incorrect because the cited lines don't support the answer to the previous question. Instead, they provide a historical background to Lewis's cultivation of soil bacteria (choice A), praise the methodology used by Lewis's team and others (choice B), and introduce an evaluation of teixobactin (choice C).