Answer: D) Pulmonary and aortic valves.
Explanation
There are two main heartbeats from a healthy heart.
The first beat is called the S1 or the lub, and it occurs when the atrioventricular valves (comprising the mitral and tricuspid valves) close.
The second beat is called the S2 or the dub, and it occurs when the semilunar valves (comprising the aortic and pulmonary valves) close.
Listening for heart beats is an essential part of cardiac auscultation.
A) in between Earth and the sun
Carbon and nitrogen are the two atoms like in each peptide bond
Answer:
it is a process whereby energy moves from one place to another
Explanation:
False
Science gains knowledge by verifying facts and evidence.