Valves, they are like flaps of muscle that keeps the blood in its place util its ready to be pumped along.
Polio affects the central nervous system and spinal cord. It can cause muscle weakness and paralysis. Polio is a life threatening condition because it can paralyze the muscles that help you breathe.
The polio vaccine is used to help prevent these diseases in children and adults.
Answer:
it should be 4:4
Explanation:
The p will stand for purple and the w will stand for white.
it would go like P | P
W | PW | PW
W | PW | PW
D Energy input from the environment is stored in food molecules
during photosynthesis.
its correct.
I would say for number three the answer would be 3
