It should be 3 or 6... Not 100% sure.
Friedrich Miescher in 1869
Answer:It went into the air through evaporation.
Explanation:
(C) they used trans-Saharan trade route to acquire expensive ivory.
Q1: The answer is seasonal changes.
Q3: The answer is sodium.
Q4: Not sure, sorry.
Q5: And then I think it is A for this one, but I am not sure.