After striking his head on a tree while falling from a ladder, a young man is admitted to the emergency department. He's unconscious and his pupils are nonreactive. Which intervention would be the most dangerous for the client

A．Give him a barbiturate.

B．Place him on mechanical ventilation.

C．Perform a lumbar puncture.

D．Elevate the head of his bed.

社会规律的特点是

A．具有鲜明的阶级性
B．不具有长久性和稳定性
C．通过人的活动实现的
D．同人的意志和意识无关