通常用于调节混凝土凝结时间、硬化性能的混凝土外加剂有()。

A.缓凝剂 

B.早强剂 

C.膨胀荆 

D.速凝剂 

E.引气剂 

A client with a known history of opiate addiction is treated for multiple stab wounds to the abdomen. After surgical repair the nurse notes that the client’s pain is not relieved by the prescribed IM meperidine hvdrochloride(Demerol)injections. The nurse recognizes that the failure to achieve pain relief from the Demeroi injections indicates that the client is probably experiencing the phenomenon of()

A．Tolerance

B．Habituation

C．Physical addiction

D．Psychological addiction