1. How far from an earthquake epicenter is an observer who measured a difference of 8 min 40 s in the arrival times of P and S waves?

I think the answer is 34.2

It is the doctrine that the us had the right and duty to expand throughout north america. it just means they believed they had the right to expand westward and they did! they stated with the 13 colonies and then they kept moving gaining different territories throughout the years

Answer (a) the itcz comes overhead for part of the year; i believe this is correct,plz check first; ///