Why is it useful for historians to base certain studies on the analysis of historical periods?
a. the major historical themes apply only to certain civilizations during certain periods
b. the ideas that characterize a particular period are unaffected by ideas from other periods
c. similar events and trend often take place on different places during the same periods
d. experience has confirmed the analyzing periods is the most effective approach to history

How has urban renewal affected poorer neighborhoods in major cities? check all that apply. 1. communities have been transformed to meet the needs of the modern population. 2. old stores and factories have been renovated and used for new purposes. 3. crime rates have increased as more money has come into the neighborhoods. 4. many community businesses have gone into decline or been forced to close. 5. a number of african americans have been displaced from their homes.