Diffusion.
diffusion acts passively, and the oxygen and carbon dioxide move to the area of lower concentration
Answer:
they are not effective against viral infections such as a cold or flu.
<span><span>Find your pulse at your wrist (the radial artery) or at your carotid artery in your neck.</span><span>Using your index and middle finger, count the number of beats you feel in 10 seconds. Do not use your thumb since it has a light pulse that can confuse you while counting.</span><span>Multiply the number of beats you count in 10 seconds by six to find the number of beats per minute. You can take your pulse three times, then take the average rate of all three to be super scientific.</span></span>
