Detailed Instructions: Here are two questions (Question1 and Question2). If these questions have the same meaning and same answer, answer "Yes", otherwise "No".
Q: Question1: Why didn't the US Army make the M1 Abrams' gun a rifled 120mm main gun instead of a 120mm smoothbore gun?, Question2: "What is that ""lump"" in the middle of the main gun's barrel on many tanks?"
A:
No