溪口内有筑坝条件，能容纳()以上的溪沟山洪来石量，可采用溪沟内筑坝拦石方案进行急滩整治。

A.3年 

B.5年 

C.7年 

D.9年 

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.