He was killed in the civil war
I believe this is called: <span> replication
Replication refers to the repetition of a study that has already been done in the past, but conducted with different situations or subjects.
The main purpose of this type of study is to find out whether the conclusion of the previous study could be applicated in different circumstances and held as a general standard.</span>
8) Principal
9) Principal
10) Principle
(Not sure about 9 though)
Answer: A) Climate
Explanation: Until the mid-20th century the largest impediment to trade between area "1" and area "2" on the map was climate. The Sahara Desert was a major impediment to trade. True, there were Trans-Saharan trade routes for centuries, but there is no denying that the desert was an inconvenience at the very least.