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The "lubb" sound (first heart sound) is ...

The "lubb" sound (first heart sound) is caused by
1. filling of the ventricles
2. ventricular contraction
3. closing of the AV valves
4. closing of semilunar valves

A

filling of the ventricles

B

ventricular contraction

C

closing of the AV valves

D

closing of semilunar valves

Text Solution

Verified by Experts

The correct Answer is:
B
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