Answer: questions are a good and easy way to start, like these one,(sorry they are not the best).Have you ever been on a roller coaster? Have you ever seen one before?
The answer is 1. the others don't make any sense lol
The lever on a lighting control console that simultaneously dims all the channels from one cut to the next is a crossfader.
A crossfader can be defined as a control on a DJ mixer that allows the mixes to be created, so nowadays is a very basic tool.
The crossfaders became common in the '70s when they were used by the DJ to make mixes.