The north of the US did not want slavery while the south did want slavery. they had a war over it (the civil war) the north won and slavery was abolished.
The RENAISSANCE was a time of renewed learning in the arts and sciences.
Answer: internal validity; External validity
Explanation:
Internal validity is defined as the piece of evidence which support a claim about a cause as regards a particular study. It is one of the most important stages to consider on the properties of scientific studies as it's important in reasoning with evidence.
External validity is described as the conclusion of a study outside the context of that study, it is the extent to which the result of the study is communicated with the situations, people.
These terms proves the validity of internal over external, making internal most considerate in studies.
There are fewer workers available to work in industral jobs
