You are attempting to administer CPR to a victim.When you blow into his mouth it is apparent that no air is getting into the lungs.What should you do ________.
A.
Blow harder to force the air past the tongue
B.
Raise the victim's head higher than his feet
C.
Press on the victim's lungs so that air pressure will blow out any obstruction
【单选题】Seeing Red Means Danger Ahead The color red often means danger-and by paying attention,accidents can be prevented.In the future,the color red also may help【51】______danger at construction sites.Thanks...