Kennedy, Carter, and Jackson.
The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
This new tunnel revolutionized transportation in Europe and overcome this physical barrier because the Swiss engineers built the world's deepest and longest tunnel in the world, increasing the effectivity of train freight transportation across Europe.
We are talking about the Gotthard base tunnel, in Switzerland. According to the article "Swiss create the world's longest tunnel," was so complex to build that engineers and workers lasted 20 years to complete. It is a tunnel for trains. It has 35 miles of longitude and crosses the Alpes mountains.
Right before the 20's started World War I happened, so many of the young men of the world were apart of that war and saw horrific things. So after the war they wanted to forget so they had as much fun and parties as they could.
Answer:because the U.S. Constitution is the supreme law of the land
Explanation: