移位股骨髁上屈曲型骨折多采用什么牵引?()
A.股骨髁部牵引
B.胫骨结节牵引
C.皮肤牵引
D.外固定架牵引
E.悬吊牵引
参考答案:A
He met many problems ________ he was going over his lessons. [ ]
A. before
B. as soon as
C. since
D. while
某自动化机床加工C6140机床主轴,技术要求为现每次抽检5件共抽检了25批。决定用-s控制图进行分析。查表得子组n=5时A1=1.342 A2=0.577 A3=1.427 B3=0 B4=2.089。
选上述题答案的原因是()。
A.控制图中点子的排列不随机
B.25点中有1点出界
C.连续4点有上升趋势
D.11点出界