Which is true of the Korean War? Helicopters were used to drop Agent Orange on the forests

North Korea flew over 1 million combat missions

It is the first war using arial combar

North Korea attacked the United States

That would be #1 from what I have read.

Explanation:

The text I read said: "Agent Orange was a powerful herbicide used by U.S. military forces during the Vietnam War to eliminate forest cover and crops for North Vietnamese and Viet Cong troops."

C) North Korea attacked the United States

Explanation:

the tallest building in the western hemisphere and the sixth tallest building in the world

adopted the practice of proskynesis, a persian court custom that involved bowing down and kissing the hand of others, depending on their rank.