Question

i. Contraction phase of heart:
ii. The structure that holds the heart valves in position:
iii. The part inside the heart that initiates heartbeat:

Answer 1

Hey!

i.            Contraction phase of heart: Systole

ii.            The structure that holds the heart valves in position: Tendons

iii.            The part inside the heart that initiates heartbeat: Pacemaker 

Answer 2

Answer:

answer is correct

Explanation:

good