While assessing a 2-month-old child's airway, the nurse finds that the child isn't breathing. After two unsuccessful attempts to establish an airway, the nurse should

A．attempt rescue breaths.

B．attempt to reposition the airway a third time.

C．administer five back blows.

D．attempt to ventilate with a handheld resuscitation bag.

新氢压缩机正常运行时内操检查描述不正确的有（）。

A、观察压缩机轴瓦温度在正常范围内

B、检查各级入口温度是否正常

C、检查压缩机振动烈度在正常范围内

D、各级出口气阀温度可以超过135℃长期运行