The explorer has discovered "A shield volcano".
Haya~!
For life on Earth, Carbon is essential for life to exist.
Explanation: I took the test
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<span>Model construction.....</span>
Proteins are made of hundreds and thousands of polymers called Amino Acid which are attached with each other in long chains. There are 20 different types of amino acids that make up a protein
Answer:
Heart valves or the closure of the mitral and tricuspid atrioventricular (AV) valves at the beginning of ventricular systole and the closure of the aortic valve and pulmonary valve at the end of ventricular systole.
Explanation:
The heart tone “lub,” or S1, is caused by the closure of the mitral and tricuspid atrioventricular (AV) valves at the beginning of ventricular systole.
The heart tone “dub,” or S2 ( a combination of A2 and P2), is caused by the closure of the aortic valve and pulmonary valve at the end of ventricular systole.
