Iran has been isolated from the rest of the world by its

language and history

radical leadership

geographic location

Answerair masses develop near the equator are warm; tropical air mass

Answer (d) may increase or decrease porosity through dissolution or deposition;

Historians are researchers of the past or people who understand the history of people. with this field, they must possess qualities such as being unbiased, patient, efficient reader, has a knack for logic and critical thinking and reasoning, disciplined, open-minded, resourceful, with good analytical ability, good reasoning skills and problem solving!