第23题: [单项选择]Conventional X-rays mainly show the difference between _________. A. bone and air B. liver and pancreas C. muscle and other body D. heart and lungs 参考答案:A 答案解析:[解析] 事实细节题。在文章第三段第一句中,对传统X光摄影使用范围的叙述是“只能分辨骨头与空气”(In addition,conventional X-rays generally different