I like 4 the best. If an organism is covered by sediment before the body decays the sediment can harden around the decaying body and the imprint will be preserved in the hardened sediment.
Answer:
Toxic sediment and nutrient that's the answer
Explanation:
<span>Answer: occurs when the aortic and pulmonary valves backfill with blood</span>
The second heart sound,that is heard in normal hearts, is generated by the closing of the semilunar valves((the aortic valve and pulmonary valve). Before that, the first sound corresponds to the closing of the atrioventricular valves.
