The attorney's question refers to what gear the witness was driving in: first, second, reverse, etc.
"Gear" can also mean clothing, particularly athletic clothing, and the witness answers as if that was what the attorney wanted to know.
The bar exam is the qualifying test you take in order to become an attorney.
"Appearance" can refer to the act of showing up or to how someone looks.
The attorney is asking "Are you here this morning because I sent a deposition notice to your attorney?" The witness answers as if he's being asked about what he looks like.
The point of the last one is that the question doesn't make any sense; it's a ridiculous question.