Answer:
C, B, A, D, E
Explanation:
RA is thought to begin with a T-cell–mediated immune response that precipitates interaction between IgG and RF that constitutes an immune response. Pannus invasion is one consequence of this interaction, the ultimate result of which is destruction of cartilage.
IgE antibodies
Hope this helps
Answer:
Lactic acid
Explanation: After exercise, lactic acid is produced from anaerobic respiration. This burns your muscles.
Well, we know that a lot of the ancient civilizations were first-handedly affected by disease. For example, Native Americans were severely impacted by the spread of pestilence. 90% of their population was completely killed off. I think that would be enough to concern them, don't you think? :P