What was the life expectancy of 1880 and 1890 in the U. S.?

What was the focus of the stanford study-pls

The map shows england and france in 1430. which statement most accurately summarizes the information provided by the map? england was sure to defeat the french in battle. england occupied land on the european continent. france was about to invade the british isles. france was more powerful than england.

The date a source was created is considered part of historical context intended audence purpose point of view