You are performing cpr on a victim and an assisting responder arrives. which of the following is most appropriate for the assisting responder to do first? 1. begin giving ventilations to the victim.2. call for a change in position to assist with cpr.3. check to see whether more advanced medical personnel have been called.4. have the first rescuer stop cpr to allow for victim reassessment.

3. Check to see whether more advanced medical personnel have been called

Explanation: When somebody finds themselves in these kind of delicate situations where someone has collapsed and is not breathing, we use CPR because it can keep people alive until Emergency services arrive. The first step is to start helping them by giving CPR and the second step is making sure that the medical personnel is on their way because they are more eligible and experienced.

b. heterotroph

explanation:

"a.) well–developed vascular system."