Which advance in medical technology has affected the standards of living of the greatest number of people in developed and developing nations?

The development of vaccines.

the answer would be option c. the chief result of u.s. participation in world war i is that, the u.s. forces ended the stalemate and led to an allied victory. after the us joined wwi, the allies had the forces they need to triumph. hope this is the answer that you are looking for.

explanation:

mark brainliest and have a great day!

athena gives perseus a mirror sp he won't directly look back at her.