Why is it useful for historians to be certain studies on the analysis of historical periods?

they required less loading and unloading

explanation:

the shipping container improved shipping because it cut down on unloading time by three weeks, eliminated wasted space, and allowed ships to carry.

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

the authority to tax.

“a committee reviews the bill and marks it up to make it more viable and to reflect interests