What reasons might be suggested for the location of civilizations along river valleys?

Is karma the same as destiny, in the sense that everything that happens to you is predetermined? do you believe that "what goes around comes around," and if so is this the same as karma? does everyone get what they deserve, in the end?

What are the biggest challenges facing the average american citizen today? explain.

Explain the reasons for u.s. neutrality during the 1920s and 1930s. how did ideas about neutrality change during the period from the end of world war i to the passage of the lend-lease act? be sure to include any events, terms, or people that may support your response.