[just another ref]

Originally Posted by MPLAHE

Another one that confused me was the following: A substitute who legally enters the game during a dead-ball period may not be withdrawn during that same dead-ball period. The correct answer was false. Following the logic of 3-3-3 and 4, a player is legal once he enters the court, and the player leaving becomes bench personnel. Is he not the "replaced" player and subject to the restrictions in 3-3-4?

The "replaced player" is the one on the bench and is subject to the restrictions you mentioned. Any other player could come in and replace the last substitute to enter the game.