The stock market crash of 1929
Answer: Lubrication
Moving parts of early machines were able to run because of the application of a lubricant such as oil, vaseline or grease.
The history of lubrication has advanced into a discipline known as tribology, which studies interactions between the moving parts of a machine.
By studying friction, wear, and lubrication, engineers are able to design bearings that prolong the useful life of rotating machinery.
Answer:
A) President
Explanation:
Since the foundation of the United States as formulated in the U.S. Constitution, the Commander-in-Chief of the Armed Forces has always been the acting President of the United States.
He had an oil monoploly over all of north america, he controlled everything to do with it, he even made the barrels for the oil. (Not personaly.) Welp im not actually sure now i have re read the question (whoops) he just lived a life of luxury, and he spent it on bribing officials, so that they didnt pass a law that disintegrated his monopoly, but that happened in the end anyway.