We know that dry and wet periods follow a cycle of 550 years because of a. people keeping records of rainfall.
tree ring analysis.
C. the study of fossils.
d the Spanish documenting it

Summarize the effects of the marshall plan on the us and western european countries

In shifting to a defense policy based upon the concept of "flexible response," president kennedy was indicating that he had grave doubts about thevalue of which previous defense policy? a massive retaliationb collective securityc containmentd air power

Why didn’t the united states participate in the league of nations? the u.s. senate did not want the country to join. president wilson did not want the country to join. the league of nations was only for european countries. the league of nations had failed to prevent world war 1