公称外径为90mm的PP-R管热熔承插连接承口管件的最小通径为( )mm。
A．9.0
B．13.0
C．18.0
D．25.0
参考答案：D
A 21-year-old primigravida has an emergency cesarean delivery under general anesthesia because of unanticipated fetal distress. One postoperative intervention is to assist her to turn every 2 hours. Which of the following conditions is this intervention intended to prevent ？（）
A．Pressure ulcers.
B．Muscular stiffness.
C．Respiratory complications.
D．Venous stasis.
醋酸地塞米松注射液（）
A．两步滴定法
B．高效液相色谱法
C．柯柏反应比色法
D．紫外分光光度法
E．四氮唑比色法 下列药物及其制剂的含量测定方法分别是
