It is called blind. a condition in which the participant is not aware if he/she is in the experimental or control group
<span>This variation be justified by:
</span>Migration to an environment different from their birthplace, and adaptation to the available food, ultimately leading to speciation. because <span>birds use their beaks to eat.</span>.
An eclipse would make sense, also can I get brainlest
Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of capillaries. Capillaries are the smallest blood vessels , they are only one cell thick, and they act as sites of the transfer of oxygen and other nutrients from the bloodstream to the body tissues. Additionally, they also collect carbon dioxide, waste materials and fluids for return to the veins.
