Answer:
B ) Valves
Explanation:
Valves allow blood to flow only in one direction and prevent the backflow.
B
(random words to reach 20 characters)
You crave drugs when you don't get the same experience without them so a lack of a desirable sensation causes drug cravings
<span>Answer:
Macrophages- WBC that combat multi-cellular parasites.
Neutrophils- most abundant type of WBC which identifies and produces antibodies.</span>
Without frequent ground fires to clear out dead brush, a woodland becomes more susceptible to catastrophic wildfires and forest fires that can completely destroy the forest.
However, large forest fires are a natural phenomenon that occur less frequently than small ones.
