Which of the following did George Pullman provide to his workers to ensure a stable work force Select the three correct answers.

He provided well-constructed homes, the availability of doctors offices, and access to shops and athletic fields.

Explanation: He provided these basic needs becuase he wanted to make sure that he had a stable working force.

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: