( يوم يسمعون الصيحة بالحق ) يعني : النفخة في الصور التي تأتي بالحق الذي كان أكثرهم فيه يمترون . ( ذلك يوم الخروج ) أي : من الأجداث .
One, two and four are limitations of psychological experiments.
In history such as World History? You should be able to distinguish the trends and differences in different periods say "Period 1 vs. Period 2" where each period represents a different range of years (in AP World History I learned it with 6 periods but it varies from year to year of when it is taught)