Why are the majority of sub-saharan african cities located along major rivers and the coast?

You're doing research for a public essay on alternative medicine. which of the following sources has the most reliable information? a.a post on a social networking site about the undesired side-effects of different alternative medicinesb.a recent government report comparing the results of alternative and contemporary medicine for a specified diseasec.an anonymous article on a medical website that claims the success of alternative medicined.a 2003 study conducted by a medical research center about the effects of alternative medicine