Answer:
External validity.
Explanation:
Whether the results of this study help us to understand the relationship between cell phone use during class lectures and work performance in real-life institutions is a question of <em>external validity</em>. Whether the conclusions of a scientific study can be applied to other institutions and other activities is a matter of external validity. External validity is the generalization of the results of a scientific study to other contexts.
Invasions by Barbarian tribes
<span>Nationalism is the act of perceiving our own nation as better/superior than other country.
During world war I, Germany initiated their war due to this feeling of superiority toward other European nations, and perceived their country as the rightful ruler of the European continent.</span><span />
the answer is D its the two biggest rules
