Answer:
The first heart sound (S1) represents closure of the atrioventricular (mitral and tricuspid) valves as the ventricular pressures exceed atrial pressures at the beginning of systole (point a). S1 is normally a single sound because mitral and tricuspid valve closure occurs almost simultaneously.
Explanation:
<span>C.) A pea is a dicot, so the radicle grows and gives rise to a main root and its branches</span>
Brocklyn...............................................
It's the small intestine that the pancreas protect