输尿管结石手术前需摄腹部平片,其目的是()
A.排除泌尿系结核病变
B.了解尿路有否感染
C.了解结石以下尿路有否狭窄
D.作最后结石定位
E.了解双侧肾功能
参考答案:D
Tom was hit on the head by the robber and was knocked _____. [ ]
A. uncomfortable
B. unconditional
C. unaware
D. unconscious
ETF与开放式基金相比最主要的区别是( )。
A.具有较低费率
B.规模不固定
C.追踪指数
D.上市交易