The oxygen that goes through alveoli and diffuses into blood capillaries. The oxygenated blood goes though aorta and is pumped by the heart and goes out through the vena cava to be distributed to the whole body. the deoxygenated blood comes back to the heart from the body and is pumped back towards the lungs. the carbon dioxide diffuses out of the blood capillaries and goes out of the body.
The rotation of Earth on its axis
A bull dozer would most likey be correct
Answer:
Carbon dioxide: Carbon dioxide is a molecule composed of one carbon atom bonded to two oxygen atoms via two double bonds. Carbon dioxide is a byproduct of exhaling and from the burning of fossil fuels. Its natural existence is in the form of a gas, which is inert and non harmful to humans in very low concentrations.
Answer:
Option). NK cells.
Explanation:
Cluster of differentiation 8 (CD8) can bed defined as a transmembrane glycoprotein that acts a co-receptor for the receptor present on T cells (TCR). The CD8 is marker for 
cells (cytotoxic T cells) as it is predominantly present on cell surface of these cells.
Along with cytotoxic cells, CD8 molecule is also expressed in surface of natural killer cells (NK cells), thymocytes, and myeloid dendritic cells.
Hence, a cell having CD8 on its surface (cytotoxic T cell) would be most similar to NK cells.
