流量一定时，管径越大，流速越（）。（KHD：基础理论知识）
参考答案：小
对ARDS的诊断和病情判断有重要意义的措施是：（）
A．血气分析（氧合指数）
B．呼吸功能监护
C．血动力学监测
D．X线胸片
Capital market efficiency is desirable, but there are limitations in achieving full market efficiency . Which of the following is least likely to be a limitation in achieving full capital market efficiency（）
A. Cost of information.
B. Limits of arbitrage.
C. Survivorship bias.
