Answer:
A. Blood would leak backwards through the damaged valves due to gravity, causing lower leg swelling.
Explanation:
The passage of blood is always in a single direction in the vein due to the presence of valves in the veins.
Any kind of vein injury or vein rupture, causes the valves in the veins to not function in an appropriate manner. The injury might result in inappropriate opening and closing of these valves. The inappropriate functioning of the valves causes the blood to flow backwards. This will eventually lead to blood pooling and putting more pressure on the lower leg veins. hence, there would be swelling in the lower legs.
The correct answer is option C, that is, physical weathering.
The weathering resulting due to the influences of changing temperatures on a rock, making the rock to split apart is known as physical weathering. There are two main kinds of physical weathering, that is, exfoliation and freeze-thaw.
Physical weathering takes place mainly in the locations, where few plants grow and little formation of soil occurs, like hot deserts and mountain regions. It takes place either via repeated freezing and melting of water or via contraction and expansion of the rocks surface layer, which is baked by the sun.
Genetic variation is advantageous because it enables some individuals and, therefore, a population, to survive despite a changing environment.
Answer:
When entering, oxygen is high and carbon dioxide is being produced, when exiting carbon dioxide is being exhaled into the air
Explanation: