It is converted into chemical energy.
Answer:
D. DDT
Explanation:
DDT is highly persistent in the environment means that it break down very slowly in the environment. The half-life for DDT is from 2 to 15 years. Half-life is the time needed for the degradation of half of the compound. Persistent bio-accumulative toxic substances (PBTs) are chemicals that break down slowly in the environment and its accumulation in living organisms are toxic. Some PBTs are dispersed through air currents while some uses other environmental pathways, resulting in contamination of regions far from their points of origin.
Since the other answer got deleted, i'll just answer it for you.
a sinoatrial node is the main pacemaker that begins each heartbeat located in the junctions of superior vena cava and the right atrium. It signals from the node that spread through the atria and determines the heart rates.