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.
Answer:
B. Erosion
Explanation:
Igneous rock (derived from the Latin word ignis meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava.
Erosion is the process of wind, water, and ice breaking down rocks tint smaller pieces. Erosion breaks down igneous rocks, metamorphic rocks and sedimentary rocks. Erosion breaks down igneous rocks in the same manner as it breaks down other rocks
Unconsciousness occurs when the brain shuts down in order to prevent any further damage to it.
These molecules need to pass through specific proteins or transmembrane proteins embedded in the cell membrane. A specific type of an integral membrane protein.