cars put pollution in the air and it harms our lungs same with smoking
mark brainliest;)
<span>The answer is a certain required chemicals must be actively
transported. Blood brain barrier is a
selective membrane that separates blood circulating from the brain and the
fluid of extracellular in the central nervous system. This is also called a
filtering mechanism, the capillaries that carry blood to the brain and spinal
cord tissue blocking the path way of the certain substance.</span>
Explanation:
It is true that the wings of the bee move very fast. The wings are smaller than their body and it is believed to be difficult for the wings to lift the whole body of the bee.
Sometimes, bees carry nectar and pollen with itself which again increases their weight. It has been found that the wings do not move up and down rather moves to and from. Since air is denser, it tries to push the air downwards and lift itself upwards.
Cross contamination means the transfer of pathogens from surface to another