2. 我选择D. 因为监测器的增加未能提高预报率,只能解释为其效率降低,inoperative的比例上升。 B只有绝对数字的增加,而比例却可能降低,应该不对。 C,battery只是inoperative的一个方面,所以有否安装battery,与结论并无关系。事实上battery只是个陷阱,原文的含义就是over half of the domestic smoke detectors are inoperative 。
Good question. I guess you mean that all of the smoke detectors in homes are battery operated. In Gmat, the answer may be acceptable. But if in Lsat, it couldnot be right , because it is a support rather than assumption. Please refer to my former explanation.