How do the respiratory system and the circulatory system exchange materials. A) by receiving hormones with their cells
B) by attaching their cells to neuroendocrine cells
C) by the diffusion of molecules across a cell membrane
D) by the movement of molecules across a synapse

C) by the diffusion of molecules across the cell membrane

answer: although many types of viruses can cause a common cold, rhinoviruses are the most common culprit. a cold virus enters your body through your mouth, eyes or nose. the virus can spread through droplets in the air when someone who is sick coughs, sneezes or talks. theres your answer

explanation: