Describe the united states role in air combat over europe during world war ii

They utilized new tactics and technologies  .

Explanation:

What is now known as the United States Air Force evolved drastically leading up to and during World War II. New technology made it possible to travel higher and faster than before. Bombers could carry more weapons than during the Great War and the role of air combat became increasingly important.

They utilized many new tactics and technologies during their involvement  

the answer is d. tariffs were raised by america's trading partners after the smoot-hawley tariff act, decreasing exports, and declining job rates.

answer; (d) i believe that the correct answer is americans finally ran out of ammunition;