how can having 100 trillion microorganisms on and in the human body keep us healthy?

Diamond, graphite, and fullerenes share what property? a. they are all made of carbon (c) bonded to a metal. b. their shape. c. they are all made of carbon (c). d. they are all good conductors.

Measuring which physical property is most likely to produce the most precise results when trying to identify a substance

Iknow the answer is a but i don't know why