In the Neolithic age, agriculture created supply of food. This development gave people the time to pursue new activities. Some people focused on making better containers. Such efforts led to the invention of the . Other people focused on making stronger tools. They used their knowledge of metalworking to begin making tools with .

kennedy used a range of this to develop a 'flexible response' plan for any international crisis. “he also expanded the it was important, because it ordered the fall of khruschev.

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: