8. Using equipment that you haven't been trained on A. OK as long as you're careful and read the directions, B. can cause major damage to your body and to the equipment . C. allows you the opportunity to teach yourself how to do a particular exercise. D. is a good way to add variety to your workout .

when in a crucial situation, after calling 911, the correct posture for delivering effective compression is the proper hand placement.

first, place two fingers at the sternum, then put the heel of your other hand next to the fingers and place hand on top of the other. lock your elbows by using your body’s weight and compress the victim’s chest with a depth of 2 inches.

moreover, do 15 compression and 2 breaths, this process must be done four times until there is a pulse or a arrive.