Answer: Valves in the veins
Explanation: The flow of the blood inside the body takes place through the veins and arteries. The oxygenated blood from the heart is supplied to the different parts of the body.
The blood flows from the capillaries to the venules and from there to the veins. The blood moves in the veins by the rhythmic movement of the smooth muscles in the body.
Most of the blood moves against the gravity so there is a chance that it can backflow so to prevent this there are valves in the veins known as one way valves.
In the vacuum of space there is no molecules. Sound waves get to your ears by bouncing off of molecules in the air. No molecules in space's vacuum means sound waves have nothing to bounce of off so they can not reach our ears meaning we hear no sound.
Answer:
C. A fossil is any trace of prehistoric life
Explanation:
None of the other answer choices are reasonable enough to be true. I hope this can help you!
Cytokinesis is the division of the cytoplasm.
Mitosis the nuclear division.
hope this helps