急性弥漫性腹膜炎最常见的原因是()
A．阑尾炎穿孔
B．急性胆囊炎穿孔
C．肠扭转
D．胃十二指肠溃疡病穿孔
E．肝破裂
参考答案：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
下列图形是控制图的控制状态的是（）。
A.A
B.B
C.C
D.D
