下列哪种操作属于非血管系统介入放射学范畴()。
A.肾动脉扩张术
B.肾囊肿穿刺治疗
C.内科性肾切除
D.肾动脉血管内支架留置术
E.肾外伤出血栓塞治疗
参考答案:B
如图所示,R1为定值电阻,R2为滑动变阻器,电源电压恒定,闭合开关S,调节滑动变阻器滑片,R1、R2两端的电压U1、U2与电流I的变化关系图象如下选项所示,其中正确的是
A.
B.
C.
D.
— So how long have you been in Beijing?
— Just a couple of days. I’m on a great tour, you know, and I ______ all the places of interest here.
A.visited
B.am visiting
C.have visited
D.have been visiting