2. which one advancement of the second agricultural revolution do you think was the most significant and why?

Technological advancement. The second agricultural revolution was strongly influenced by the development of machinery and led to the industrial revolution. 

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!