Help please due today

In a publicly held corporation, - o stockholders rarely trade their stocks o stocks are not usually traded at stock exchanges o a large number of stockholders can buy and sell stock o family members are excluded from holding stock

What period of history refers to the time when people did not have written records

Which statement is a good description of a model? a) models are a description of nature based only on one or two variables. b) models are testable ideas but they are not very to most people. c) models are a description of nature that predicts more accurately than real events. d) models are an approximiation of a real system that omits all but most essential variables in a system.