Question

question 6 of 10 what is the most common molecule in living things? a. h2 b. co c. co2 d. h2o

Explanation:

Water ($H_2O$) is essential for life - it is involved in many biological processes like metabolism, transport of nutrients and waste, and maintaining cell structure. Living organisms are composed mostly of water. Hydrogen gas ($H_2$), carbon - monoxide (CO) and carbon - dioxide ($CO_2$) are not as abundant as water in living things.

Answer:

D. $H_2O$