第8题: [单项选择]下列液体回声何项描述不妥() A. 胆汁是无回声 B. 尿液是无回声 C. 陈旧性血肿是无回声 D. 新鲜的血肿大都表现为无回声 E. 发生纤维化钙化的陈旧性血块回声增多 参考答案:C 答案解析:陈旧性血肿由于血液淤积并逐渐机化,因此超声表现会在无回声的基础上逐渐出现减弱回声、甚至增强回声,而不是单纯的无回声。
第26题: [单项选择]The flash point of a liquid refers to the temperature () A. at which a liquid will give off inflammable vapors B. at which a liquid will burn steadily C. at which a liquid will explode D. that a liquid must reach before it will flow readily 参考答案:A