Ahistorian is awarded a grant to study the effects of industrial air pollution on sugarcane farms in brazil. his research will focus on which major historical theme?

Interactions between humans and the environment

Explanation:

This is one of the main themes that the historian will be studying. The study of history can be divided in a few major historical themes. This is because many historical events follow similar patterns or deal with similar problems. In this case, if the historian studies the effects of industrial air pollution on sugarcane  farms, he is studying the interactions between humans and the environment. This is a theme that can be traced back to the development of agriculture.

answer: alexander hamilton

explanation: alexander hamilton was george washington's right hand man. he took an early role in the militia as the american revolutionary war began. in 1777, he became a senior aide to general washington in running the new continental army.

during the 20th century, the role of the vice president has evolved into more of an executive branch position. now, the vice president is usually seen as an integral part of a president's administration and presides over the senate only on ceremonial occasions or when a tie-breaking vote may be needed.