The answer bnb is true becuase without desity in anything nothing would circulate
The kidneys secrete an enzyme called renin
<span>Most elephant shrew species were first describedin the 1800s by scientists who ... DNA evidence is very conclusive and some say 99% accurate, however it is possible to challenge it based upon faulty collection and/or faulty lab techniques.</span><span>
</span>
Answer:
The pressure differences on either side of the valve.
Explanation:
The heart valves open and close passively because of pressure differences on either side of the valve. When pressure is greater behind the valve, the leaflets are blown open and the blood flows through the valve. However, when pressure is greater in front of the valve, the leaflets snap shut and blood flow is stopped.
Hope this helps!
have a blessed day
