Why is lighter skin beneficial in parts of the world with low UV exposure? (Use vitamin D in your answer)

How does oxygen move from the respiratory system to the circulatory system? a. by pumping through the heart b. by circulating in an artery c. by moving across a synapse d. by diffusion across a capillary wall

What are the seven economic and social goals?

For this question look at the hydropic diagram water that is heated by the sun evaporates. select the number that represents it.