在对儿童患者进行人工呼吸开放气道时,耳垂和下颌角连线与地面所成的角度为多少度?
参考答案:60度。
Computer cannot remember who _______; it simply does what _______.
A.has used it; it is told
B.will used it; it was told
C.uses it; it has told
D.has used it; it told
控制图上的控制界限通常表示为()
A.均值
B.变异系数
C.精密度水平
D.准确度水平
E.标准差的倍数