可产生外毒素的菌群：（）
A.宋内志贺菌
B.福氏志贺菌
C.鲍氏志贺菌
D.痢疾志贺菌
E.空肠弯曲菌
参考答案：D
一束光垂直射向平面镜，入射角是 ______度，反射角是 ______度．
What state is a process in when it cannot run because it needs a resource to become available
A．Ready
B．Interrupt
C．Blocked
D．Running
